The flowsheet was based on laboratory tests wherein troublesome factors were eliminatedahead of design and construction. The flowsheet provides for unit arrangement of equipment and for added flexibility. Two-stage closed circuit crushing (with an apron feeder for control to the jaw crusher), provides ore for grinding circuit. Crushed material is conveyed to a Screen and the oversize is returned to the secondary cone crusher. The screened fraction drops to a reversible conveyor, thence to fine ore bins.
Adjustable stroke belt ore feeders regulate the feed to two 5 x 10 Steel Head Ball Mills in closed circuit with Cross-flow Classifiers. Each classifier discharge flows by gravity to two banks of 6 Cell No. 18 Sp. Sub-A Flotation Machines. The grind, 65 mesh is held as coarse as possible to reduce grinding costs and still attain maximum recovery. Each flotation section provides six cells for roughing and three cleaning stages with provisions for elimination of one or more stages for cleaning when type of ore permits (flexibility incorporated in Sub-A Machines).
The flotation concentrates are pumped to a regrind circuit to produce desired final size meeting specifications. The final ground concentrates are thickened and filtered. Filters are directly above concentrate storage bins.
The mill site near the mine is accessible to water, power, labor and supplies, and includes adequate space for expansion and tailings disposal. The topography makes gravity flow through the mill possible and allows for delivery of ore direct from mine cars to mill.
Equipment selected gives simplicity and flexibility in operation and allows for changes in tonnages and character of ore. Due to class of labor available, complicated controls and adjustments were eliminated where possible. The machinery selected and installed permits duplication of units for expansion.
As field welding was not available, bolted steel ore bins were installed. The machinery foundations, building foundations, retaining walls and floors are concrete. The flotation machines are mounted on low piers to allow for drainage. An operating platform of wood was installed between flotation machines to give clear working space. The flotation machine launders were designed to permit changes in cleaning stages without shut-downs or prolonged delays, and permits circuit adaptation to changes in ore characteristics. A tailings thickener permits partial reclaiming of water, in dry seasons.
The correct design of a milling plant can mean its success or failure when in operation, the difference between profit and loss. Maximum metallurgical results with low operating and maintenance costs requires thorough study and sound planning. Selection of equipment and construction features must be balanced with available finances and a minimum sacrifice in operating efficiency. Here is a typical small plant where proper design resulted in a successful operation.
This 75-ton, lead-zinc-gold-silver mill was based on a flowsheet developed through batch and continuous laboratory tests. These studies showed single stage crushing and grinding to 65 % minus 65 mesh was adequate for this operation. Tests indicated that over 70% of the gold, 40% of the silver and 60% of the lead was recoverable in the grinding circuit. Therefore Unit Cell and a Mineral Jig section were installed. Adequate flotation capacity to selectively float the lead and zinc was provided, together with a small concentrating table to visually show results of flotation. The zinc and lead concentrates are pumped v direct to a 4-foot by 4-disc Filter with two compartments. This filter was placed on top of the concentrate bin which location provides desirable operating room around the filter and could be seen from almostanywhere in the mill. The concentrate bins were of laminated wood constructionsturdy and inexpensive. Filtered concentrates drop directly into the bins.
Thickeners were eliminated due to initial installation expense and extra housing required because of climate. Low dilution, by keeping sprays in flotation launders to a minimum and ability of Vertical Pump to handle frothy pulps makes this possible.
The mill site was selected several miles from the mine at a point where water, power and tailing disposal area were available, and where it was accessible even during the heavy snow season. The site is on a natural slope, permitting gravity flow in the mill with minimum pumping requirements.
Equipment is arranged as compactly as possible without crowding and without sacrifice of working space, in order to keep the mill building to minimum size. This keeps capital investment low, and reduces heating costs during cold weather. The mill building, of wood construction with laminated wood roof trusses with one-quarter pitch, was covered with insulating material and corrugated sheet material. This construction was most suitable due to the climate and
low cost of lumber in the area. A small steam boiler and unit heaters were installed for heating. Mill and crushing buildings are on concrete foundations extending about four feet below the ground line. Concrete floors of 4 to 6 thick are sloped per foot, permitting slushing down with a hose.
Crushed ore conveyor is enclosed in a conveyorway for weather protection. Fine ore bin is housed within the mill building to prevent freezing. An inclined belt feeder with variable speed drive gains elevation to grinding mill. Feeder was designed with sloping hopper to reduce load on the belt of feed discharging from the bin.
Foundation for Ball Mill was made of reinforced concrete and cast in one section to prevent distortion and misalignment due to possible settlement or shifting of the foundation. Ball mill, unit flotation cell, jig, and classifier were arranged for easy access and operation. The ball mill was equipped with a spiral discharge screen to remove oversize material ahead of unit cell and jig. The 30 spiral classifier was equipped with a rotating motor-driven paddle to remove troublesome wood chips from classifier overflow screen.
The two six-cell No. 18 (2828) Sub-A Flotation Machines were elevated on timber bents with operating platforms between the machines; this gave space belowmachines for pipe lines, launders and concentrate pumps. Reagent feeders were grouped together above flotation machines and conditioners at elevation of filter floor for gravity flow of reagents, and for accessibility.
The mill control office located in the center of the mill, was designed with large windows so almost every machine in the mill could be seen. Operating floors most frequently used were kept as nearly as possible on the same level to reduce stair climbing for the operators. Mill was designed so two men per shift could handle this plant very well.
A gallery was provided in the trussed-roof section, the length of the building, for the installation of main electrical circuits, safety switches, and magnetic motor controls. This kept most of the electrical items away from splash and dirt. All wiring was selected oversize to reduce voltage drop, giving higher operating efficiency and reduced electrical maintenance. Totally enclosed motors were used for reduced maintenance. Push button start-stop controls were placed at the machines and in the mill control office, so that any machine could be controlled from either place.
A typical problem confronting a mining operation of moderate production is how to design a mill at a reasonable cost incorporating modern equipment and essential basic principles of materials handling with the minimum construction and mill costs.
The first step in mill design is the flowsheet based on reliable ore tests. The mill capacity and equipment sizes as shown has been selected as an example for treating 500-550 short tons of ore per 24 hours per day. Two-stage grinding is to all minus 65 mesh for an average ore. Sufficient flotation capacity is included for a medium to slow floating ore. Thickening and filter capacity is selected for a 10 to 1 ratio of concentration as would be the case when treating a 3% copper ore with the copper mineral being chalcopyrite. In such case it would be necessary to filter 50 to 55 tons of concentrates each day. The use of a mineral jig or flotation unit cell in the grinding circuit is recommended. A simple test in our laboratory can tell you whether a coarse product can be recovered easily in the mill circuit.
The general design will apply to other ores with slight modification. The arrangement provides for ultimate use of gravity flow as is noted by the absence of pumps and elevators. The basic machines in plan and elevation are shown along with a flowsheet of the crushing,grinding and mill recovery circuits.
Mine run ore is fed to the primary jaw crusher by a heavy duty apron ore feeder over a grizzly. Crushed ore from the primary crusher is fed over a vibrating screen ahead of the cone crusher to remove fines. The crushing plant is normally designed to crush the entire daily mill tonnage in one shift or, at the most, 2 shifts.
Two- stage grinding provides the grinding economies outlinedin DECO Bulletin B2-B13. In the wet grinding circuit, a rod mill takes the entire feed at and reduces it to approximately 14 to 20 mesh. This mill is normally operated in open circuit with the classifier and ball mill. Usually there is a power saving with this grinding arrangement and often a substantial saving in the cost of the entire mill can be effected by reducing to a minimum some of the requirements in the crushing plant due to this method.
The ground ore overflows the classifier at -65 mesh and approximately 25% solids and is shown being conditioned ahead of flotation. Two parallel banks of Sub-A Flotation Machines on the same floor level are shown for roughing, scavenging, cleaning and recleaning. This arrangement in the flotation circuit provides maximum flexibility in the flow of material, high grade selective concentrates, and low final tailings.
Normally 10 square feet of thickener area is provided for each ton of concentrates per 24 hours which gives reserve capacity to accommodate normal filter maintenance without shutting down the flotation circuit.
In thedesign of any milling operation, continuity of flow should be given first consideration and all weak links eliminated. The old saying an hours delay means no profits today is even more important in our modern milling circuits where labor costs are high.
Many typical design plans and flowsheets are available for your use. Templates of all basic machines, scaled to 1-foot in plan and elevation facilitate laying out these plants. Free tests are made by the Laboratory to check your grinding, thickening and filtering requirements.
If you have a mill design problem, large or small, it will pay you to consult with us. We want to help your engineers in their design work. This service will enable your engineers to lay out your mill at the millsite thus saving design, construction and operating expense. Your completely designed basic plant may already be available in our files with only minor changes necessary to modify it to fit your specific application.
Shanzhuo is a high-tech company integrating R&D, production and distribution, and provides crusher, sand making, grinding equipment, portable crusher plant, etc. mature products and solutions used in aggregate, mining and waste recycling.
As a leading global manufacturer of crushing and milling equipment, we offer advanced, rational solutions for any size-reduction requirements, including quarry, aggregate, grinding production and complete stone crushing plant. We also supply individual crushers and mills as well as spare parts of them.
Shanghai Shanzhuo Heavy Machinery CO., Ltd. is a collection of R &D, production, sales and service in the integration of high-tech enterprises. Employed for more than twenty years, it is all along worked on ore crushing, sand making and grinding mill equipment, provided high-level application solutions and high-end complete sets of equipment. For highway, railway, large engineering projects of hydroelectric.
China manufacturing industries are full of strong and consistent exporters. We are here to bring together China factories that supply manufacturing systems and machinery that are used by processing industries including but not limited to: stone crusher, crushing plant, crusher machine. Here we are going to show you some of the process equipments for sale that featured by our reliable suppliers and manufacturers, such as Crushing&milling Plant. We will do everything we can just to keep every buyer updated with this highly competitive industry & factory and its latest trends. Whether you are for group or individual sourcing, we will provide you with the latest technology and the comprehensive data of Chinese suppliers like Crushing&milling Plant factory list to enhance your sourcing performance in the business line of manufacturing & processing machinery.
A Stone Crushing Plant is one-stop crushing installation, typical materials like limestone, granite, river gravel, basalt, etc., the plant produces different sizes of gravels and sand which can be used for constructions.
Stone Crushing plants may be either fixed or mobile. A stone crushing plant has different stations, primary, secondary, tertiary, etc., where different crushing, selection and transport cycles are done in order to obtain different stone sizes, for fixed plant different stages combines together to form a complete stone crushing plant.
Raw materials are evenly and gradually conveyed into jaw stone crushing equipment for primary crushing via the hopper of vibrating feeder. The crushed stone materials are conveyed to crushing plant by belt conveyor for secondary crushing before they are sent to vibrating screen to be separated. After separating, qualified materials will be taken away as final products, while unqualified materials will be carried back to the stone crushing equipment for re-crushing. Customers can classify final products according to different size ranges, also according to different requirements, final products sizes can be adjusted from the crusher machines.
Crusher, Jaw Crusher, Grinding Mill manufacturer / supplier in China, offering Good Quality High Capacity Mining Stone Cone Crusher Machine, Cone Crusher Mining Equipment for Sale, Hot Sale Gold Ore Mini Stone Crusher machine Price and so on.
Shanghai Zenith Mining and Construction Machinery Co., Ltd. is an international and professional company, which engages in power making equipment and mining equipment. The Zenith crushing and grinding equipments such as Jaw Crusher, Impact Crusher, Vertical Shaft Impact Crusher, Cone Crusher, Vibrating Screen, Vibrating Feeder, Belt Conveyor, Trapezium Mill, Ultrafine Mill and Vertical mill are widely used in electric power industry, metallurgy, mining, chemistry, steel, oil building materials industry. ...
With the fast development of the refractory material and new energy vehicles, graphite resources are focused in recent years. There are two different type graphite: Artificial graphite and Natural graphite. Prominer provides the complete solution of graphite processing plant including crushing, grinding and flotation plant to make natural flake graphite concentrate. For graphite concentrate deep processing for anode material, we can also supply spherical graphite spherical grinding & shaping production system and spherical making test service. Besides, Prominer has various resources linking to chemical & thermal purification technology, coating technology, carbonization technology and half cell & full cell testing to make Li-battery anode materials and expandable / expanded graphite.
Every graphite mine has unique characteristics which need to be determined in advance. Therefore, it is of crucial importance to determine graphite flake morphology, primary flake size and liberation size. Typical flake graphite deposits are gneissic and consist mainly of feldspar, quartz and mica. The size of the graphite flake is a very important fact under commercial consideration. Therefore, it is in the best interest of a flake graphite producer to maximize the amount of large flake. Prominer is experienced in choosing the suitable grinding mill to reserve high yield rate of big flake graphite.
With the development of expanded graphite and anode materials industry, there is much requirement on high purity graphite product. It is very hard to reach the grade above TGC 96% just by the stage grinding and flotation processing. To get higher grade above TGC96% or even above TGC 99.95%, deep processing should be applied. General processing technologies for graphite ore are summarized as below:
It is necessary to undertake the lab test or even pilot test for determining primary flake size and liberation size, improving the TGC grade as high as possible, meanwhile to find the suitable grinding-flotation way to reserve the big flake size graphite. It means that any processing reducing the size of constituent flake must be minimized. The ball mill is used for the primary grinding stage, thereafter the vertical stirred mill with ceramic grinding media is the best choice for intermediate regrinding stages.
Graphite purification furnace is used for continuous high temperature purification of graphite powder to match increasingly stricter environmental protection requirements. We have continuous type and pusher type for different purpose purification process. It is continuous loading and discharging under high temperature reducing the energy consumption and shortening the production cycle. The furnace adopts electrical resistant or induction heating that the temperature can reach up to more than 2600C. Most of the impurities become gas, but the graphite will remain because of its heat resisting property. Both high temperature and chemical method can be used to satisfy the high purity requirement. The furnace uses high efficiency filter system, which can trap the dust and corrosive gases coming from the purification process.
Graphite used for high tech products such as Lithium ion batteries or fuel cells demands higher purity than typically upgraded by flotation. The chemical purification technology should be considered for further purification of graphite concentrate to TGC 99.99%. A basic process is thermal treatment in the presence of caustic reagents to dissolve siliceous impurities such as quartz, feldspar or mica. The graphite concentrate is mixed with caustic reagent and calcined at elevated temperatures. After calcination the graphite is leached with water washing away dissolved impurities. In order to get ultra-high purity graphite, the fine intergrown minerals residing between the graphite layers have to be removed. Thus, one or multi-stage acid washing with different acids or combinations is applied to remove impurities that are insoluble at alkaline conditions.
The spheroidization process is the most important step for making cathode & anode materials. Prominer has the ability to provide the complete spherical graphite grinding system including primary crushing mill, shaping mill, air classifier and dedusting system. It is widely used for processing cathode materials such as lithium iron phosphate, cobalt acid lithium, lithium manganate and Li-NiCoMn Lithium ion materials, and anode materials including natural graphite & synthetic graphite grinding and spheroidization processing. It is highly efficient to get potato-shaped graphite particles with high yield rate between 40-70%. We do also have the batch type shaper mill to improve the tap density.
For making the natural graphite anode materials, the coating and carbonizatino treatment are the key processing steps to determine the cathode and anode materials performance for rechargeable battery. Prominer maintains a good relationship with the suppliers that can provide coating and carbonization system.
Prominer has been devoted to mineral processing industry for decades and specializes in mineral upgrading and deep processing. With expertise in the fields of mineral project development, mining, test study, engineering, technological processing.
The size reduction operation in the plant takes place as a sequence of crushing and grinding processes. In crushing, particles are reduced in size to such a level that grinding can be conducted, while grinding allows to achieve the desired liberation size.
Besides, the process of comminution can be simple or complicated depending on the nature of the ore and the suitable degree of liberation. For example, hard rocks that come from blasting can be big as 1m in size, and require multiple stages of crushing and grinding. In addition, if the valuable mineral is finely disseminated in the ore the grinding size can be down to 40 microns, which can be achieved by two grinding stages at least.
Initial size reduction is accomplished by Jaw, cone, and gyratory crushers. It can be applied in the mine site as well as at the start of the milling plant. Medium size grains require jaw, cone, and gyratory crushers as well as roll crushers to be reduced in size. The comminution of smaller coarse particles is done by Cone, roll. Hammer crushers and rotary breakers.
Grinding is conducted in mills. There are three grinding stages, coarse grinding (hundreds of microns), fine (tens of mictons) and ultrafine grinding (<10 microns). Tumbling mills, rotary breakers, and pendulum mills are mostely used.
Both crushing and grinding require energy to reduce the ore size. However, in grinding operations we consume much more eneregy than crushing, up to 100 times ( thousands of kw compared to tens in crushing).
Additionally, some chemical reagents can be used to minimize the energy consumption of grinding, because grinding energy is minimum at pH of the point of zero electrical charges of the material surface which is known as Rebinder effect.
Wears are most important in grinding compared to crushing. Because as far we go to finer sizes wears increase due to more collosion requirment for further size reduction. Besides, the grinding media generates extra wears production
The demand for high pressure grinding rolls (HPGRs) increases recently, as they respond to features requirements. Skewing designs for HPGRs are investigating for reducing wear and promoting better grinding.Get in Touch with Mechanic