Heavy medium beneficiation refers to the beneficiation process carried out in a medium having a density greater than 1000 kg/m3. The density of the medium is generally selected between the density of light minerals and heavy minerals in the mineral. When the density of the medium is strictly controlled (fluctuation range ≤20 kg/m3), the density difference can be only 50~100 kgm3. The minerals are effectively separated. Heavy ore dressing has been used in industry for more than 70 years. It is mainly used in ore pre-selection, that is, selecting gangue or surrounding rock under coarse-grained conditions, reducing the amount of ore selected by fine grinding and increasing the grade of ore selected. Currently, it has been widely used in the treatment of iron, manganese, lead, zinc, tin, antimony, coal gangue, diamond and other metal and non-metallic mineral aspects. The upper limit of the selected stone size is 50~150mm, and the lower limit is 2~3mm. The heavy medium beneficiation process includes ore preparation, medium preparation, ore sorting, medium removal, and medium regeneration. The disadvantage is that the preparation of the medium, the removal of the medium and the regeneration of the medium require a complete set of facilities, which is relatively complicated. The advantage of heavy medium dressing is that (the density of the medium is prepared according to certain requirements), the separation density can be precisely controlled, and the minerals with small density difference can be effectively separated. The processing capacity per unit area is large and the cost of mineral processing is low. The average small and medium-sized factory is less used. Second, jigging beneficiation Jigging ore dressing is one of the main methods of gravity beneficiation and belongs to the deep tank sorting operation. The jigging beneficiation can process almost all kinds of mineral raw materials except for very fine materials. The process is simple, the equipment processing capacity is large, and some kind of final product can be obtained in one sorting. Therefore, it is widely used in production. The use of jigging to treat raw coal accounts for about 40% of the total coal. For metal ore, it is the main method for processing coarse, medium iron ore, manganese ore and chrome ore. It is also used to sort out the coarser parts of tungsten or tin ore that are unevenly embedded. The use of jigs to treat gold ore, primary ore containing strontium , barium, titanium and zirconium and sand ore is widely used, and is also the main method for selecting diamonds. The greater the density difference of the mineral to be separated in the ore, the wider the range of the selected particle size. For example, for the gold ore mine, when the feed size is less than 25 mm, it may be selected without classification, and the lower limit of the recovery particle size may be 0.04 mm. However, the classification of general metal ore can effectively improve the sorting index and improve the processing capacity of the equipment. On the premise that the specific gravity difference is ≥1.25 and the ore monomer is dissociated, the optional size of the jig is 150~2mm, and the size range of other minerals is 50~0.1mm. Up to 0.04mm. Third, shaker dressing The shaker belongs to the flow film dressing type equipment, which is developed from the plane chute and is self-contained by its asymmetric reciprocating motion. The shaker is a common equipment for sorting fine ore. When the metal ore is treated, the effective particle size range is 3~0.019mm, and the upper limit particle size can be 10mm when coal is selected. The outstanding advantage of the shaker is that the sorting accuracy is high, and a high-grade concentrate or waste tailings can be obtained by one sorting, and multiple products can be taken out at the same time. The flat shaker is easy to handle and easy to adjust. The main disadvantage is that the equipment covers a large area and the processing capacity per unit of factory area is low. The standard shaker (4500×1830) has a throughput of 0.12~2.2t/h. The finer the particle size, the smaller the throughput. Fourth, chute dressing The chute beneficiation belongs to the bevel flow sorting process. The slurry is fed to a inclined inclined groove or inclined surface. Under the action of water flow, the ore group is loosely layered, the upper layer of fine minerals is quickly discharged outside the tank, and the lower layer of heavy ore is retained in the tank or discharged from the lower part at a low speed. After picking up separately, the concentrate and tailings are obtained. The chute is the earliest mineral processing equipment. The utility model has the advantages that the device structure is simple, the investment and the production cost are low, the coarse and medium grain chutes have higher processing capacity, and the disadvantage is that the sorting accuracy is low, the recovery rate is also low, and after the jig and the shaker appear The use of chutes is greatly reduced. At present, the mineral mud chute is used to treat the fine-grained grade (-0.074mm) low-grade sand ore of rare metal ores such as tungsten, tin, gold and platinum . V. Spiral beneficiation Spiral beneficiation is a beneficiation process carried out in a long groove curved into a spiral shape. It is still in the category of bevel flow dressing, but here the inertial centrifugal force generated by the slurry in the rotary motion is utilized to promote the zoning of fine heavy minerals on the groove surface. And discharged continuously. (1) Spiral concentrator The spiral concentrator has a simple structure and no moving parts. The floor space is small, the unit processing capacity is large, and the operation and maintenance are relatively simple. The machine is suitable for processing sand mines with less mud. The feed size is 2~0.1mm, and 0.5~0.1mm is the best. Desliming or grading should be carried out in the treatment of mudstone ore products with high mud content, otherwise the concentrate quality and recovery rate will be reduced. The disadvantage is that the beneficiation is relatively low, and the selected concentrates generally need to be reprocessed and then selected. (two) spiral chute The flow of the slurry on the spiral chute and the separation principle are basically the same as those of the spiral concentrator. It is only suitable for the treatment of fine-grained ore in the spiral groove surface with a larger gentle width and a larger area where the slurry flows in a laminar flow. The spiral chute also has the advantages of simple structure, large processing capacity, convenient operation and low production cost. It is suitable for treating 0.6~0.03mm vein or sand mine, but it is unfavorable for sorting when the mud content is high. The ore dressing enrichment ratio is also lower. 6. Centrifugal dressing Centrifugal beneficiation mainly accelerates the sedimentation and stratification speed of fine-grained grade by means of centrifugal force, and is suitable for processing fine-grain grade minerals of -0.1mm. Because the production cost is relatively high compared with the general gravity selection method, and 37~19 Micron size recovery is very good. At present, it is mainly used to process fine-grade materials such as tungsten. Compared with the shaker, in the processing of 0.037~0.019mm materials, the centrifugal concentrator has the advantages of less floor space, large processing capacity and energy saving, but its ore dressing enrichment ratio is low, and its concentrate is produced. A belt chute is required for selection to achieve the final concentrate. The centrifugal concentrator is mainly used to replace the paving chute process. Seven, wind dressing Wind beneficiation is the process of selecting mineral raw materials by air density in the air medium. The particle size and shape also have an effect on the sorting. The advantages of wind beneficiation compared to re-election in aqueous media are: (1) The operation does not consume water, the product does not need to be dehydrated, and the winter transportation will not freeze. (2) The equipment structure is simple, and the infrastructure construction fee and operating fee are both low. However, wind beneficiation also has major shortcomings, which are manifested in: 1) Sorting accuracy is much lower than wet re-election, and product quality is also poor; 2) Raw materials should be dedusted and classified before being selected. 3) Can not handle wet ore. 4) During the sorting process, the equipment should be tightly sealed and dust collected. The diffused dust is harmful to the environment and to workers. Because the wind beneficiation process is relatively complicated and the ore dressing efficiency is low, its application has great limitations. Currently mainly used for the treatment of coal, asbestos and other non-metallic ores, especially for the processing of mineral raw materials that are not suitable for water. Xuzhou Xuqi Heavy Machinery Co., Ltd. , https://www.xqheavy.com
1. Heavy medium dressing