mineral processing technology and mineral processing equipment

In flotation beneficiation plant , main euipments are important such as ball mill, flotation machine, crushing machine etc. And the flotation reagents are also important for flotation process, the reagents used in flotation are usually divided into three classes: Collectors : organic chemicals which make the surface hydrophobic and hence the mineral is capable of being collected in the process. Frothers : organic chemicals which reduce the surface tension of the water to stabilize the bubbles into a froth layer at the top of the flotation cell to make concentrate removal easier. Modifiers : organic or inorganic chemicals used to modify the slurry conditions to enhance the difference in surface chemistry between the valuable and gangue minerals. Let’s introduce frothers and modifiers in this article Frothers Frothers are surfactants, usually organic heteropolar compounds such as alcohols or polyglycol ethers. Due to the heteropolar nature, the frother adsorbs at the air/w...

In flotation beneficiation plant , main euipments are important such as ball mill , flotation machine , crushing machine etc. And the flotation reagents are also important for flotation process, the reagents used in flotation are usually divided into three classes: Collectors : organic chemicals which make the surface hydrophobic and hence the mineral is capable of being collected in the process. Frothers : organic chemicals which reduce the surface tension of the water to stabilize the bubbles into a froth layer at the top of the flotation cell to make concentrate removal easier. Modifiers : organic or inorganic chemicals used to modify the slurry conditions to enhance the difference in surface chemistry between the valuable and gangue minerals. Let’s introduce collectors in this article Collectors Collectors are generally heteropolar organics with a charged polar group and an uncharged non-polar group. The non-polar group is typically a hydrocarbon chain and in the be...

Beneficiation dewatering-filter The separation of solids from liquid by gravity can be easily done by batch or continuous sedimentation processes. The underflow, however still contains appreciable amounts of liquid and the overflow can contains some amount of solids. Further removal of liquid is necessary for some down stream operations. The removal of this liquid is usually possible by passing the suspension through a semi-permeable membrane which is designed to hold the solids and permit the liquid to pass through. In effect the membrane forms a screen. In the early stages of separation across this membrane the solids deposit forming a second semi-permeable medium or cake. These two layers then form the filtering medium for the remainder of the slurry. The structure of the filtering cake changes continuously as more particles deposits with time. The main changes relate to permeability and porosity of the filtering zone. The permeability of the cake depends on the particle size, s...

In   beneficiation plant , thickeners are essentially clarifiers producing a clearer over flow. The design considerations are based on the settling rates of the slowest settling particles and conditions for minimum disturbance of the medium (water) through which the solid particles are allowed to settle. To achieve these objectives cylindrical tanks with conical or flat bottoms are used and the velocity of the feed slurry entering the settling tank is minimised to reduce turbulence in the settling tank. A schematic diagram of a typical thickener is shown in Fig.1. The feed in the form of slurry is generally guided by a launder, which is laid at a slope just sufficient for the slurry to flow without depositing any solids. The feed launder terminates in a feed well located at the centre of the tank. The feed well is designed to break the fall of the slurry and dissipate the energy. Fig1. Sketch of bridge type thickener The feed well is concentric with the rake driving shaft. T...

After initial liberation of a mineral constituent from its ore by crushing, grinding and screening, separation of minerals by size are normally attempted by a classifying process. In mineral processing plant operations, classification and separation of mixtures of fine and coarse particles and also of lighter and heavier particles may be performed in a wet or dry state. The majority of separations are carried out in a liquid environment because of an increased efficiency. The basic technique employed is to allow particles to settle under gravity in a liquid medium (usually water). The higher terminal velocity of irregular shaped, coarser, heavier particles allows these particles to reach the bottom of the vessel at a faster rate compared to particles that are smaller and lighter. Removing the settled particles while the others are still settling offers a simple means of a separation. For very small particles, like clay or silt, whose size approaches colloidal dimensions, long times a...

Disintegration and size reduction of some ores is possible in tumbling mills without the aid of grinding media. Grinding mills in which comminution takes place without grinding aids are known as Autogenous Grinding (AG) mills or Fully Autogenous Grinding mills (FAG). These mills use large lumps of rock as the grinding media. Mills that use intermediate size rock or pebbles as a grinding medium are also autogenous mills but are known as pebble mills. Mills that grind hard ores with fracture characteristics that do not lend themselves to fully autogenous milling are charged with a small amount of steel balls to assist in the size reduction. These are known as Semi-autogenous Grinding (SAG) mills, hi the mining industry all of these types of mills are in use. The disintegration and size reduction of ores in AG/SAG mills is brought about by a combination of impact, attrition and abrasion forces during mill rotation. Particles at the toe of the mill charge receive the maximum impact forc...