Sustainability is today?s buzz word in design, development, manufacturing and processing. In other words, it is imperative to control the environmental impact of any project or initiative. In aggregate washing, that means being water wise. Obviously, sound water efficiency practices protect surface and ground water resources and ultimately keep producers far more profitable.
Water shortage in quarries is common, especially in Australia, where rainfall is the second lowest of all continents. Producers may wish to gain the benefits of washing, but have very little water on-site, or they may not have the appropriate footprint to properly maintain a settling pond. Or, if the operation is portable, it will face a variety of water use challenges from site to site.
In any event, the washing of sand and aggregate results in the discharge of dirty water from wet screening decks, sand screws, or sand classifiers. The waste water typically carries fines out to a series of settling ponds. Although the common method of treating wash water fines, it is not the most sustainable. As such, water wise washing operations are employing hydrocyclones, water clarifiers, flocculant systems and belt presses to efficiently reclaim and reuse wash water in some cases, even eliminating the need for a settling pond.
TRADITIONAL SETTLING PONDSAs they require no additional capital equipment, settling ponds may seem to be the most cost-efficient choice. However, the method can be problematic, said Bob Gralton, president of Wisconsin-based Clearwater Industries, which provides custom-designed water treatment equipment for the aggregate industry. Mr Gralton cited a number of settling pond disadvantages: ? Water recovered for washing may be lost to evaporation or percolation in the pond, which requires the operator to provide ?make-up water? to the plant.? The real estate for large enough settling ponds may not exist at the plant site.? The cost and time of cleaning the ponds with a dragline or excavator may be excessive and inefficient especially the fine material that flows downstream and settles very slowly.? Dirty water may get back to the plant, limiting production, producing washed material out of spec, or even shutting down production.? Ponds may present hazards to nearby equipment and to workers.
However, settling ponds suit some sites, said Mr Gralton, particularly for ?the producer who has a large area where the dirty water can be deposited and the fines need never be recovered?. He added that the perfect example is the exhausted portion of a large quarry which acts as a settling pond. ?Clean water is recovered from the opposite end of the pond and the fines settle down in the deep quarry bottom never to be dealt with again,? he said.
WATER CLARIFIERSWater clarifiers are valuable to the producer keen to eliminate settling ponds altogether, and reclaim 90 per cent of the water immediately. ?For producers who have an area that has already been mined and will be reclaimed, a good clarifier can pump the solids to that area, and it never needs to be conveyed, loaded or hauled again,? said Mr Gralton. He stressed that while clarifiers require a significant initial capital outlay, they have minimal maintenance and operating costs.
Portable clarifiers are an addition to the market. Clearwater Industries recently introduced its new Model 2000 portable water clarifier for use in mining and sand and gravel applications. It allows operators to take a dirty water stream, and produce clean water immediately, concentrating the fines or solids to a thick state. Via this streamlined ability to recycle and reuse valuable water resources, users can meet water conservation targets, ensure an uninterrupted quality water supply, avoid the risks of plant shutdowns due to water shortage, minimise the costs of water consumption and waste water management, and reduce environmental impact.
The benefits of a portable, closed-circuit clarifier are well illustrated by examining its use in a rural-based sand and gravel processing application. An Idaho-based sand and gravel operation constantly works seven local sites, and completes custom crushing and washing projects for regional customers. The operation is as efficient as its water resource management and when water is tight production may come to a halt. In past years, its portable washing projects had been limited by water availability at certain sites. Most jobs had to be scheduled in the northern spring as the highest water table was available then. Ultimately, the operation would always run out of water and by June it would have to stop as there wasn?t enough recharge water to fill a well back up.
Consequently, the operation upgraded its processes with the purchase of the Model 2000 portable, closed-circuit water clarifier. As its name indicates, the unit delivers up to 7.5 kilolitres per minute, at 20 per cent solids by volume. The system is complete with an automated flocculant system, a 30kW drive, and a hydraulically-driven mud pump that will move mud up to 243 metres. The Model 2000 typically requires three hours for setup with features such as fold-up catwalk handrails.
The new clarifier allows the portable operation to recycle and reuse water, while conserving its makeup water. As a result, this opens up new opportunities for them sites with little or even no water, or no place for a settling pond.
?Traditional closed-loop systems typically require ponds for water discharge and for feed water to the plant,? explained Mr Gralton. ?Alternatively, the unit used by this portable operation has a clean water tank placed right on the clarifier. From this tank, the water is pumped directly to the wash plant. The totally self-contained unit includes a dry polymer feed system, hydraulic package, control panels, a mud discharge pump, and a clean water return pump to supply the wash plant. With this closed-circuit operation, at least 90 per cent of the water is reclaimed, and the need for a pond is eliminated,? he said.
Fresh water is pumped to the wash plant from a 56 kilolitre supply tank parked next to the clarifier. After the material is processed, the dirty water is discharged into a sump that sits remotely from the clarifier. From there, the discharge water is pumped into a flocculant tank atop the clarifier where the polymers are added. Next, the flow separates into twin clarifying tanks where the suspended solids settle out of the waste water. Then the clear water overflows back into a clean water tank, which is mounted on the clarifier. This tank has a ?keep-full? system on it. If its float drops, water is added from the makeup tank to keep the system in balance. The thick mud is pumped from the bottom of the clarifiers, usually into an excavated area for drying. ?The big thing is that the unit produces a drier mud and that saves big on water,? said Mr Gralton.
Doing portable washing the old way has always involved trucking in large volumes of water. Ponds are filled and then they evaporate or leak into the ground even in instances where ponds are shotcreted or paved. Portable clarifiers allow the operation to bypass the clean water pond altogether.
HYDROCYCLONESHydrocyclones are tapered cones that receive the dirty wash water at a high velocity. The water travels in a tight circle within the cone and centrifugal force throws the largest particles to the outside of the cone where they slide down the cone and out the bottom. Rather than discarding all the particles into a settling pond, the cones can recover the #200-mesh and larger material, which can be sold as aglime, mineral filler, lining for utility trenches, mortar, grout additives and more. This means that the hydrocyclone can deliver a welcome return on investment.
Mr Gralton explained that while the hydrocyclone will effectively remove coarse material from the dirty water, it will pass the midsize and very fine particles out to the ponds. The resulting fine material in the pond is extremely ?slurpy,? which hampers any periodic cleaning of the pond, as the material must be dipped from the pond, cast to the side, and allowed to dry. This dried material is hard to handle, and equally hard to load into trucks. For this reason, Mr Gralton suggested that producers send the very fine overflow from the hydrocyclone to a clarifier, or to a pond that is not intended for cleaning.
FLOCCULANTSFlocculants rapidly settle out virtually all of the suspended solids in a dirty water stream. They are required when operating a water clarifier or belt press, but are optional when using a settling pond. They cannot be used with hydrocyclones. Liquid flocculants require very little hardware and can be introduced via a small chemical metering pump with some dilution water added. However, liquid flocculants are not environmentally friendly and often separate or stratify in the container before use. Dry flocculants are more environmentally friendly but require more sophisticated equipment to get them into the solution properly. ?It is imperative to find a vendor with the expertise, products, and resources to select the right flocculant for a given application,? said Mr Gralton, who added that their use does not eliminate the settling pond, but does eliminate some problems associated with ponds.
Mr Gralton suggested that flocculants are a good solution for the producer who wants to guarantee that only clean water gets recirculated back into the plant, for those who want to reduce the number of settling ponds on the site, and for those who don?t mind ?dipping out? a pond, but want to do it far more efficiently.
BELT PRESSESBelt presses have been considered the ultimate in fines recovery and dewatering but Mr Gralton said that they are complex and costly to run as they must be accompanied by a ?thickener? tank, a flocculant system and an extensive foundation with sumps. The operating cost is further escalated by the need for a full-time operator.
The belt press is preceded by the thickener tank which acts like a low performing clarifier. Dirty water is fed into the large-diameter thickener where flocculants are added. Clean water runs off the top of the thickener and back to the plant. Mud is pumped from the thickener at 25 per cent solids by weight, and is sent to the belt press. En route to the press, more flocculants and coagulants are added to stiffen and condition the mud prior to dewatering in the press. The mud is laid upon a synthetic belt where gravity drains off the loose water. Another belt comes down and ?sandwiches? the mud layer. Then the belts run around rollers and mechanically compress the trapped mud, squeezing out the water. The resulting fines (70 per cent solids) are discharged from the machine in a ?hamburger patty-like? consistency and can be stacked prior to loadout.
Mr Gralton explained that prior to the the new ?plate and frame presses,? the belt press was the only solution for the producer who had no available property for a settling pond or an area to deposit fines for reclamation. ?If the producer wants to immediately stack and haul the fines, the belt press had been, until recently, the only solution,? he said. Mr Gralton suggested that the plate and frame press is now the new trend. Plate and frame presses are dewatering machines that utilise pressure to remove the liquid from liquid-solid slurry. ?Although the plate and frame press requires a significant capital investment, and must also be preceded by a clarifier, their use does not require the addition of costly flocculants and does not need to be manned by a full-time operator. That cuts much of the operating costs,? he said.
SUSTAINABLE SOLUTIONSIt?s been said that water is ?the oil market of the future?. With that in mind it is important to perform a water audit to determine where and how you use water at your facility, not only in the aggregate washing process, but in every facet of your operation. Develop a maintenance program that routinely inspects all plumbing equipment and fixtures, water lines, spray systems, valves and pumps. Metering at strategic points in the facility helps to detect leaks and maintains minimum flow rates. But above all, employ the optimal reuse and recycling systems for aggregate washing. It pays to be water wise.
Lenntech is introducing the innovative Closed Circuit Reverse Osmosis (CCRO) technology to the water and process industry in Europe. CCRO is revolutionizing the purification and recovery of water across a variety of industries.While traditional RO systems create excess brine waste, do not use water supplies efficiently and consume too much energy - CCRO systems will conserve water, reduce brine waste up to 75% and energy consumption up to 35%, compared to traditional reverse osmosis designs. CCRO systems are also drastically reducing fouling and scaling on membranes which results in less maintenance and down time.Side-by-side comparisons between traditional reverse osmosis and CCRO have demonstrated breakthrough improvements in fouling and scaling resistance most notably at Padre Dam where water recovery rates of 96% with no requirements for Clean-In-Place have been obtained; outpacing the industrys highest recovery rates of 85% (and numerous CIPs) for comparable water. CCRO systems work by recirculating pressurized feedwater until a desired recovery level is reached. Brine is replaced with fresh feed without stopping the flow of pressurized feed or permeate. CCRO systems achieve recovery by recirculation, not with multiple membrane elements and stages in series, and can therefore reach any desired recovery percentage in a single stage. This patented semi-batch reverse osmosis process has demonstrated recovery rates of up to 98% in single stage brackish systems, saving more water and reducing more waste than traditional one-, two- and three-stage reverse osmosis systems. Recovery is adjustable, providing unmatched flexibility. Cross flow supplied by a circulation pump washes the membrane and salinity cycling disrupts and greatly reduces scaling and fouling. Cycle times are shorter than the induction time for scale deposition and frequent and complete brine rejection can stop and even reverse precipitation, making very high recovery rates possible even from difficult source waters. Furthermore, massive fluctuations in salinity and pressure within the feed-brine side of the reverse osmosis membranes prevents biological growth.
The low initial pressure of each CCRO sequence means a lower operating pressure and less pump energy than required in traditional RO systems. When treating seawater, it uses just enough power to overcome the waters osmotic pressure, resulting in a record low energy consumption of 1.45 kWh/m3. Short membrane arrays and high cross flow also allow CCRO systems to operate at higher average fluxes without exceeding conventional reverse osmosis membranes manufacturer's flow or recovery specifications. CCRO systems can be used for anything traditional reverse osmosis is used for, including but not limited to: industrial process water food, beverage, and pharmaceutical ingredient water boiler water pretreatment irrigation water desalination brine concentration municipal wastewater treatment Because of their record-setting water recovery rates and unmatched operational flexibility, CCRO systems are especially valuable when handling sites with: Variable feedwater High silica concentrations Expensive liquid waste disposal Strict liquid waste volume limits This is a clear paradigm shift in water efficiency and reliability. CCRO systems minimize the largest cost associated with reverse osmosis system operation, wastewater disposal, which can be reduced by 50% to 75% and provide paybacks of under a year. CCRO systems come with an industry-leading maximum recovery guarantee, operating at up to 98% recovery and allowing you to achieve your sustainability goals. Closed Circuit Reverse Osmosis is boosting our customers financial, environmental and operational competitiveness.
Woodlark Island (locally known as Muyuw Island) is located on the northern margin of the Woodlark Basin, some 600 km east of Port Moresby. There are some series of gold deposits at the Woodlark Project: Kulumadau, Busai, Woodlark King, Munasi. The geology of the island consists of basement Palaeocene-Eocene tholeiitic basalt and sediments (Loluai formation) overlain by mid- Miocene calc-alkaline to shoshonitic volcanics (Okiduse formation), which host the majority of known gold mineralisation. The island is relatively flat, with the highest point, Mt Kabat just 243 m above sea level. Most of the island is covered by a Pleistocene age coral reef formation (Kiriwina formation), masking prospective volcanic sequences.Busai and Kulumadau are both interpreted as structurally controlled epithermal gold deposits. The deposits show evidence of complex paragenetic assemblages and variable degrees of structural overprint. The main difference between the two deposits is the overwhelming amount of brecciation and cataclasis at Kulumadau as compared to Busai. Both deposits remain open at depth and along strike.Due to the significant presence of post- mineralisation Kiriwina formation sediments masking much of the prospective geology, very little regional scale exploration exists.The extensive resource drilling database, geophysical surveys and limited surface exploration all indicate the widespread occurrence of gold mineralisation well outside the defined resources. Major regional structures associated with known gold resources are evident on geophysical images and form the principal targets for exploration.
The project will involve open-cut mining of gold reserves at the Kulumadau, Busai and Woodlark King deposits using multi-staged pit designs, with a stripping ratio of 3.9:1 over the life of the mine. Waste rock will be deposited in engineered waste rock dumps located adjacent to each pit. Mining Plus was engaged to complete the mining components of the DFS, including optimisation, design and scheduling and preparation of a detailed operating and capital cost estimate to enable the generation of an Ore Reserve.The study has shown that the three mining areas can be developed in a practical sequence to mine 1.1 Moz of gold and provide sufficient feed to the processing plant for 13 years. Pit Designs and Ore Reserve.The Ore Reserve was generated from the Mineral Resource Estimate produced by MPR Geological Consultants with the appropriate modifying factors applied for dilution. This Resource model was used in an open pit optimisation process to produce a range of pit shells using operating costs and other inputs derived from all previous studies and then verified as the DFS was finalised.Geotechnical drilling and analysis was completed by Peter OBryan and Associates to DFS level. The resultant recommended design parameters were used to approximate the overall pit slope angles for the pit optimisation runs, and the final wall angles for the designs.The optimisation resulted in four discrete pits, two at Woodlark King and one each at Busai and Kulumadau.Individual designs were completed for each discrete area of Busai and Kulumadau, plus a number of starter pits were designed to allow reduced pre-strip durations and the early access to high grades ore.Mine Schedule.The mine schedule was developed to ensure 2.4 Mtpa of ore is available to feed the processing plant once commissioned. The initial pre-strip period is 9 months and involves the stripping of 5.5 Mt from Stage 1 and Stage 2 pits at Kulumadau and the build-up of 450,000 tonnes of ore on the stockpile at 1.45 g/t Au.The planned mining rates are maintained below 10 Mtpa for the first three years of mining and then rise to 20 Mtpa by the sixth year. These mining rates are driven by the tonnage and grade requirement to ensure that the mine plan achieves gold production levels in excess of 100,000 oz per year for as long as practical.The mining period is expected to last approximately 9 years excluding pre-stripping operations, however there is an additional four years of low grade stockpile reclaim after mining has been completed.
The process plant design for the Woodlark Gold Project is based on a robust metallurgical flowsheet designed for optimum recovery with minimum operating costs. The flowsheet is based upon unit operations that are well proven in industry.The treatment plant design incorporates the following unit process operations: Primary jaw crushing to produce a coarse crushed product. A SAB milling circuit comprising a SAG mill and a ball mill in closed circuit with hydrocyclones. Gravity gold recovery and treatment of concentrate by cyanidation and electrowinning. A CIL circuit to leach and adsorb gold and silver onto carbon. A pressure Zadra elution circuit, electrowinning and gold smelting to dor. Dewatering of CIL tails slurry. Tailings slurry pumping via overland pipe to a deep sea tailings placement facility. The grinding circuit is fed directly from the primary crusher, i.e. there is no coarse ore stockpile or surge bin to d ........
The i150 Gravity Concentrator is the smallest of the World famous iCONs. This is a gravimetric concentrator that uses enhanced gravity (Gs) to concentrate the free heavy minerals.It is also known as a centrifugal concentrator because of the centrifugal action of the spinning bowl. The process uses only water and an electric motor to concentrate the precious heavy minerals from a slurry.
iCON is a family of mineral processing equipment specifically designed to recover fine gold and other precious metals including such as silver, paladium and platinum. The product line includes concentrators, slurry pumps, vibrating screens and modular plants.
iCON was designed by the professional mineral processing engineers of Falcon concentrators. iCON has all the quality, reliability and performance you would expect from Canadian designed and patented equipment.
iCON integrates the proper level of sophistication for small scale and artisanal miners. There are no complicated computer controls. iCON can be serviced with hand tools available in remote and/or developing areas of the world.
iCON integrates the proper level of sophistication for small scale and artisanal miners. There are no complicated computer controls. iCON can be serviced with hand tools available in remote and/or developing areas of the world.
Its fine gold recovery features were designed for the United Nations Global Mercury Project. iCON has the support of many governments around the world for its ability to recover precious metals without the use of Mercury or Cyanide.
Upon entering the spinning bowl, the feed begins to spin. As it climbs the bowl the material is stratified/classified by weight. The heavy particles are trapped in within the fluidized riffles. The bowl is periodically rinsed producing a rich concentrate.
Cycle Time: iCON concentrators require only 1 to 1.5 minutes to rinse the rich concentrate from the bowl. Simply pause the feed, slow the bowl to minimum RPM and gently rinse the riffles with the rinse wand. Then resume full rpm and continue feeding the slurry. A typical process may involve feeding for 1 hour then rinsing for 1.5 minutes: repeating.
All iCON products include a Variable Frequency Drive. This allows the user to specify the RPM of the motors. The VFD is an inverter which conditions the power allowing for smooth and predictable operation due to unstable electricity in your mining region or erratic generator output. The VFD is also a Soft Start which minimizes the in-rush current and allows the motors to start with minimum load on your generator.
In order to install your iCON you will have to consider the following: suitable footing, electrical supply, clean/pressurized water supply, feed method, tails removal method, concentration collection. You will also need to consider the height of the concentrator relative to the slurry input and tails output.
It is important to use the same size hose as the barb to supply this process water. A smaller hose, long hose or hose with bends/restriction will restrict the water flow and limit the pressure to the concentrator.
The process water should be fed from a dedicated supply line and pump. Connection to a manifold where other people may be using this same supply may cause wild fluctuation in the pressure and lead to unpredictable gold recovery.
When the supply pump is located near the concentrator, a HP centrifugal pump is generally sufficient. If the pump has to lift the water vertically or over a long distance the pump capacity may reach 2 HP or more.
One will have to consult the pumps curves to know if it will be sufficient for long runs or high lifts. Domestic/City water is typically not sufficient due to long supply runs and small diameter pipes. Garden hoses will always be problematic due to their long length and tendency to kink/bend.
The i-CON is the newest addition line of world class enhanced gravity concentrators for the recovery of precious metals and heavy minerals.The i-CON is personal, small scale mining equipment which provides artisanal, small scale and recreational miners state of the art technology in centrifugal concentration.
Although produced for small scale mining, the i-CON is backed by 20 years of experience producing enhanced gravity concentrators for the worlds largest industrial mines. It is a fully functional primary concentrator that has been designed to be a compact, easy to use, fully portable mineral processing solution. It is designed to be very reliable and contains only one moving part.
The i-CON will allow small scale and artisanal miners to recover dramatically finer particles of gold and related minerals than is possible with any other small scale or traditional mining system. In many mining areas the fine particles are the most common; however, these are often unintentionally discarded due to inappropriate concentration practices and are never recovered.
The i-CON, with its variable speed 150 G force concentration system, will allow the capture of these valuable fine particles. It will not only increase the value of every kilogram of material mined by recovering precious metal that was previously discarded due to inefficient concentration practices, but it will also greatly reduce (and hopefully eliminate) the dependency of these miners on mercury and other harmful, toxic chemicals.
Through the involvement and cooperation of leading international aid and development organizations, the i-CON Project has the capability of being the center of large, cooperative, community improvement projects.
The i-CON has the potential to make a significant difference to the lives of people engaged in small scale and artisanal mining around the world by not only increasing income, but also by reducing the use of toxic chemicals at the same time.
The iCON i series of concentrators use a batch process. Your cycle time will depend on the grade and weight of your feed. A heavy or rich feed will need a shorter cycle time. The iCON i series concentrators can be cleaned out in 1 minute.
The throughput of the i150 centrifugal concentrator is nominally 2 tons per hour. If you have large material in your feed, if you have a heavy feed or if you are using iCON to upgrade a concentrate the throughput will be reduced. All ores and all processes are different. Each user must assess their situation as with any mineral recovery process.
The number 1 application for iCON i150 worldwide is Hard Rock. The 2TPH capacity and the ability to recover fine, flat milled gold are ideal for iCON. The major mines of the world use gravity concentration in their grinding circuits. The concentrators can recover over 90% of the overall production of major/professional mines.
A typical Hard Rock application would involve a crusher and ball mill. The material would be size classified using a cyclone in closed-circuit or simply a screen in semi-closed circuit milling. After the mill the material will pass through the concentrator. The major mines have a recyclic load. Their processes are designed for the feed to pass through a concentrator multiple times before passing to the tails.
A Hard Rock operator may choose to run 1.5 tons per hour of a high grade ore. He may choose to rinse the bowl every 20 minutes. Here, he would have run 500 kg in 20 minutes and collected 1 kg of concentrate. That is a concentration ratio of 500 to 1.
The concentrate will still need to be upgraded or cleaned to have a sellable product. Some miners around the world are choosing to collect the concentrates from multiple mine sites and clean the cons at a regional secure facility. This is known as pre-concentration.
When scavenging old tails the operator must understand that there is a reason the first miner missed this gold. It may be that it was poorly milled and needs to be re-milled to liberate more gold. In order to recover what another team missed the operator must pay attention to the details and be prepared to adjust their process as required. To understand your ore and how much gold you can expect to recover, IGR recommends testing your samples at lab.
This photo shows what your concentrate may look like.A sluice box is a gravity concentrator. Lets say you put 1000kg of feed over your sluice. At the end of the day, you may have 50kg of concentrate.
This concentrate is not bright and shiny, in fact, it looks just like the feed material. This material has to be post processed to further clean your cons and give you a sellable product. Although a sluice can give you a very high concentration ratio, it is not effective for recovering fine gold. In the case of sluice operations, miners are choosing iCON to reprocess old tails and recover the values left behind by sluice operations.
When using an enhanced centrifugal concentrator, you may put up to 1000 kg into the process and get 1kg out. This will be a concentrate. It will look just like the feed material. Some people choose to sell this concentrate while others choose to continue refining it to shiny, clean, high grade gold.
Any placer miner or dredger understands the vast amount of concentrate you will accumulate. They also understand the incredible amount of work required to clean the cons. Considering that a concentrate is already heavy, an i150 operator may run 1 tph through a concentrator. He may choose to rinse the bowl every 6 minutes which means after each 100 kg of feed. Here the i150 will produce 1 kg of cons from 100 kg of feed.
Placer miners also understand the need to classify their concentrate. Lets say a placer miner is processing inch material. He will have this coarse material and the finest sands in his sluice concentrate. The first step here is to classify or separate this concentrate into at least 2 sizes of material. The iCON IGR 100 Plant will handle this process for you. The screen will separate you material into 2mm+ and 2mm- sizes. (+/- 10 mesh) The fine material will be pumped to the concentrator and the coarse material will go to the nugget trap.
You may choose to wash your sluice directly into an iCON Slurry Pump. The pump could then move the material to your screen to greatly reduce the daily labor involved in cleaning your sluice, lifting, storing and transporting the material.
The small physical dimensions of the i150 and IGR 100 Plant make them mobile. The internal structures make them easy to clean from batch to batch or sample to sample. The i150 capacity makes it ideal for processing samples from individual drill holes. Overall the i150 is ideal for processing any volume from individual drill holes up to bulk sampling at 2 tons per hour.
The iCON IGR 1000 Plant can process up to 10 tons per hour. It is skid mounted for mobility. For larger volume bulk sampling the IGR 1000 Plant may be right for you. This pilot plant will give you confidence in the various values across your deposit and in the process of using a grizzly, scrubber, screen and concentrater.
Tables and bowls have been proven to be very effective for final cleaning. They use no chemicals are safe for the environment and your family. They are fun and provide immediate gratification after each cleanup you will see high grade gold.
Regional processing is becoming more common around the world. Miners are using iCON at their site and transporting a small volume of concentrate to regional processing plants. This is becoming the method of choice where hard rock miners have learned the value of their tails and are using the iCON to pre-concentrate their product.
This is the recommended method of the Global Mercury Program. Without pre-concentration the volume of material to treat and the amount of chemicals are tremendous. Concentration allows the operator to treat a reasonable amount of material either on site or at regional facilities serving many mines.
This is not recommended due to the environmental impacts and the effectiveness of bowls and/or tables. When practising whole ore amalgamation a miner will place mercury directly into the ball mill or sluice. In this case 100% of the ore is exposed to mercury. When a concentrator is used the amount of ore can be reduced dramatically to a small amount of concentrate 1 ton (1000 kg) of ore could be reduced to 1 kg of concentrate. If the miner chooses to amalgamate the concentrate only a fraction of the mercury would be used and only a small percentage of the ore would be exposed to Hg.
i150 has a Invertek VFD which is a single phase drive with 200-240/1/50-60Hz Single phase input and 230/3/60Hz 3 phase output. The motor is a 3 phase motor 208-230/3/60Hz which has to wire to the output of the VFD.
Wait dont throw those old electronics in the garbage, theres gold in them there things. How about putting it in your pockets instead of someone elses pocket? Laptops, phones, cameras, and the like are filled with gold plated circuit boards even printers and scanners have gold, silver, and copper, even platinum in them. Gold is a precious, conductive, and pliable metal that retains a stable value better than many commodities. Its chemical properties make it useful for the manufacture of computers parts and electronics. Some people find it profitable to attempt to extract the gold from these scraps, then refine and sell it. This complicated process requires chemical expertise as well as access to various chemistry equipment. However, with the right knowledge, experience and tools, you can remove valuable gold from computer parts, other discarded electronics. Things You Will Need: Scrap electronics Rubber gloves Rubber apron Goggles Hydrogen Peroxide 3% I got from local pharmacy. Muriatic acid 31% local hardware store. Methyl Hydrate is 99.9% methyl alcohol it is used for fuel line antifreeze and can be purchased at your local hardware or automotive supply. Funnel filter I used a drip coffee filter 2 large glass containers I like coffee pots for chemical heat. Stir stick glass or plastic Weigh scale mine is accurate to 1/10th of a grain. Blow Torch hot enough to hard solder. Borax Clay bowls just about anything that has a melting point 500o above the melting point of gold will do. Measuring cup anything you can use to make a 2:1 mix will do. Although no special skills are needed one should follow all chemical and heat safety procedures.
Collect any gold-containing metal scraps to which you have access, including jewelry, computer processors, old telephone wiring or gold tooth crowns. Keep in mind that outdated electronics are likelier to produce parts with a high enough level of gold to make the procedure worthwhile. This is the gold I collected in a bucket over three months. Sort the gold into circuits that need cleaning, gold plated parts, gold plated pins, gold fingers, and solid gold large and small. Use a magnet to separate all gold plated steel this needs a different process than I am demonstrating.
Apply all safety gear correctly before working with chemicals and do this outside as the fumes are nasty. Put the gold fingers and clean circuit boards in the coffee pot, in another container mix two parts muriatic acid and one part hydrogen peroxide and add to the coffee pot until it just covers the gold fingers and wait a week giving it a stir daily. Since I have a week I will move on to processing my solid low grade gold parts.
My RCBS scale is accurate to 1/10th of a grain when setup right however do not go by the Oz to grain chart on the scale. A grain is a grain however a troy Oz is 1/12th of a troy pound and a regular Oz is 1/16th of a pound so a Troy Oz is 480 grains not 437.5 grains. Setup the scale remembering to zero it by adjusting the screw on the left.
Cupellation is a process where ores or alloyed metals are treated under high temperatures and controlled operations to separate noble metals, like gold and silver, from base metals like led, copper, zinc, and others present in the ore or alloyed metal. The process is based on the principle that precious metals do not oxidize or react chemically, like the base metals; so when they are heated at high temperatures, the precious metals remain apart and the others react forming slags or other compounds. This process has been in use since the Bronze Age and still used today able to raise the gold and silver content to 95%, however the process cannot separate silver from gold, but this is good enough for me. Cupellation is simple weigh the solid pieces of low grade gold, burn the crap out of it until you get no more slag and it becomes a nice bright yellow bead, and then you weigh it after it cools. My solid low grade gold parts with garbage attached went from 180 grains to 75.9 grains of high grade gold with no garbage attached.
A week has passed and it is time to collect your gold flakes and dust from your cleaned fingers and circuit boards, after a week the acid darkens and with a stir the flakes of gold can be seen floating around in the pot. Pouring the acid into a coffee filter the acid passes through the filter leaving the gold behind, save the acid do not dump it down the drain. Next dump the remaining fingers and circuit boards into a deep plastic tray and add water, sort out the cleaned of gold parts, put the cleaned parts in the waist and save the un-cleaned parts for re-dipping. After you have sorted the circuit board parts pour the water off through the coffee filter and flush with methyl hydrate to clean. Since the methyl hydrate is 99.9% methyl alcohol it cleans and dries the gold flakes better and faster than water, water will cling to the gold flakes and give you a false weight.
There are basically two methods of melting gold flakes and dust to recover gold available to the average person, the mercury method called Gold-Mercury Amalgam with its obviously toxic by-products and the Borax Method. I do not recommend the mercury method it works but it is extremely toxic for generations. The Borax Method is a technique of artisanal gold mining, with its basis in the principle that borax reduces the melting point of all minerals, including precious metals like gold. The melting point of gold is 1063 C, which is a higher temperature than can be obtained by cheap torches and burners. By adding borax to the heavy mineral concentrate, the melting point temperature decreases, allowing people to melt gold out of their concentrate and salvage. By using borax, no mercury flour is produced, and gold recovery increases.
Take your cleaned gold flakes and weigh them, this tells you how much you lose in melting and cupellation when melting the flakes. Heat your clay bowl, dont worry if the bowl cracks or splits, add borax to the hot bowl, when the borax melts add the gold flakes and more borax then heat until you get a nice bead of gold, let it cool and weigh to see how much you lost.
A great instructable, here in the UK trying to just get Muriatic acid is almost impossible unlike the USA where you can get it from just about any hardware store. many thanks for putting this instructable together.
I got a question. I have been refining gold pins with nitric acid. The issue is this. When i melt it using the coffee filter the gold comes out white. But when i don't use the coffee filter the gold doesn't loose its golden color. What is happening ?
You can usually get Muriatic Acid at pool supply places in Canada (if you live in a large city, that is) fairly easily (most at 30-32%). In the UK, Muriatic Acid is sold as 'Spirits of Salt' as a domestic cleaning product (usually at percentages that the US calls industrial grades, 32 - 38%) which you will want to be exremely careful with.
Your tutorial is AWESOME Boss! question... So common household borax (typically found in cleaner isle at grocery store) lowers Melting point of gold right? Now if I were doing this process over the stove with crushed rock with gold in it, what supplies would I need and the process? I believe I saw muriatic acid and hydrogen peroxide.
All that time it took to design and build postponed your ability to generate income. What if we told you we've got a library of pre-engineered plants ready to build, rapidly install and produce profit?
Superior replacement crusher parts are taken from the same warehouse used for our manufacturing operations. That means you get an equal part, with equal quality, thats designed exactly for your machine.
At Superior, were vertically integrated. Thats just a fancy way of saying we manufacture about 95% of the materials that make up your portable plant. Were one of the only manufacturers in the world who can claim this but more importantly, it offers our customers the truest access to a custom-designed processing plant.You see, most portable plant manufacturers offer customization, but they only control the materials they manufacture (typically just the chassis). We dont stop there
For example, weve modified our crushing, screening and washing equipment to be more compatible with portability. That might include changing its size, adjusting the weight or altering a shape for proper clearance.After everything fits and specifications are confirmed, we go further and study the whole plant.
If one of our standard plants doesnt meet your needs, were glad to customize for you! Were happy to install a competitors crushing, screening or washing equipment on a Superior chassis. The world is big enough for all of us!
We always have been and always will be a privately-owned company. That means we can add more employees to our customer service team without Wall Street breathing down our neck. Isnt that the way it should be?
(1) one CRS Horizontal Shaft Impact Crushing, Screening & Recycling Plant, Portable Closed Circuit including Crush Boss Model 4142 horizontal shaft impact crusher with 32 tall x 43 wide feed opening, Andreas design two stage impact curtains, hydraulic curtain adjustment & crusher housing opening, heavy duty 4 bar enclosed rotor, custom feed hood with closed circuit side return chute & chain curtain, Simplicity 45 wide x 16 long vibrating grizzly feeder with 11 impact deck and 5 long adjustable spacing grizzly bar section, 25 h.p. electric motor feeder drive; 8 x 12 reinforced steel plate receiving hopper, under grizzly chute to combine bypassed fines with crushed product, Simplicity 5 wide x 16 long two deck incline vibrating screen with electric motor drive, two 24 wide x 8 long cross conveyors for discharge of oversize from decks #1 & #2, 24 wide x 28 long side mounted return conveyor to close circuit back to crusher feed hood, 42 wide under crusher-screen feed conveyor, 48 wide under screen discharge conveyor, self-cleaning recycling permanent magnetic separator with revolving stainless steel clad rubber belt with electric drive mounted on structure over screen feed belt, all electric plant with 200 h.p. crusher motor, electrical switchgear enclosure, (stand mounted) with main breaker, variable speed drive for feeder, starters for all on-plant motors plus (2) spare plugins for off-plant motors, remote operators control panel; all mounted on a tandem axle trailer with walkways around screen, crusher operators platform, California permitable Peerless 16 tire axle assembly and hydraulic stabilizer package with gas powered engine/hydraulic pump with reservoir complete with valves and hydraulic lines to (4) hydraulic jacking legs.
(1) one CRS Horizontal Shaft Impact Crushing, Screening & Recycling Plant, Portable Closed Circuit including Crush Boss Model 4142 horizontal shaft impact crusher with 32 tall x 43 wide feed opening, Andreas design two stage impact curtains, hydraulic curtain adjustment & crusher housing opening, heavy duty 4 bar enclosed rotor, custom feed hood with closed circuit side return chute & chain curtain, Simplicity 45 wide x 16 long vibrating grizzly feeder with 11 impact deck and 5 long adjustable spacing grizzly bar section, 25 h.p. electric motor feeder drive; 8 x 12 reinforced steel plate receiving hopper, under grizzly chute to combine bypassed fines with crushed product, Simplicity 5 wide x 16 long two deck incline vibrating screen with electric motor drive, two 24 wide x 8 long cross conveyors for discharge of oversize from decks #1 & #2, 24 wide x 28 long side mounted return conveyor to close circuit back to crusher feed hood, 42 wide under crusher-screen feed conveyor, 48 wide under screen discharge conveyor, self-cleaning recycling permanent magnetic separator with revolving stainless steel clad rubber belt with electric drive mounted on structure over screen feed belt, all electric plant with 200 h.p. crusher motor, electrical switchgear enclosure, (stand mounted) with main breaker, variable speed drive for feeder, starters for all on-plant motors plus (2) spare plugins for off-plant motors, remote operators control panel; all mounted on a tandem axle trailer with walkways around screen, crusher operators platform, California permitable Peerless 16 tire axle assembly and hydraulic stabilizer package with gas powered engine/hydraulic pump with reservoir complete with valves and hydraulic lines to (4) hydraulic jacking legs.Get in Touch with Mechanic