In addition to heavy media beneficiation , other re-election methods can be used for pre-selection, but most of them use equipment with large processing capacity, and industrial applications include jigs. Raw ore comparison table Plant selection Leb Blabeck Mezica Raw ore mining volume tons / day 2000 30 ~ 600 1800 ~ 2000 Metal content% 　 　 　 Pb (full) 0.9 3.8 3.6 Zn (sulfide ore) 7.4 5 2.6 Pb+Zn 8.3 8.8 6.1 Lead-zinc ratio 01:08.2 01:01.3 01:00.7     Leob's rather poor lead ore is pre-selected by heavy medium sorting (see table below). The enriched heavy products are finely ground and then enter the flotation to obtain lead concentrate and zinc concentrate. The heavy medium is selected by using galena as a weighting agent. Pre-selection separation of coarse-grained gangue 　 Leb Blabeck Mezica 1. Adoption method Heavy medium dressing Skimming Floating method  2. Equipment Hidden Hebrew Box Sorter Moving sieve jig and Harz jig Wimco cylinder sorting machine 3. Weighting agent Galena 　 Silicon iron 4. Media weight 2.92 　 2.76 5. The ore particle size (mm) accounts for the weight of the total ore. 3 to 30 2 to 20 3 to 50 6. The main component of coarse gangue accounts for the weight of total ore. 72.1 　 83.3 % of work weight dolomite Calcite Calcite content    Pb% 51.7 　 56        Zn% 0.07 35.5 67.3 loss    Pb% 0.85 0.11 0.15        Zn% 3.89 0.76 0.8 　 5.93 　 　 The high lead content of the Blybeck ore is treated by warm mechanical beneficiation and flotation. The jig obtains coarse concentrate and removes some of the gangue from the ore. The wet mechanical method yields a large amount of medium ore, which is subjected to fine flotation for flotation. 1 Air Suspension Compressor Lincoln air suspension compressor lincoln navigator,lincoln town car air suspension replacement,lincoln town car air suspension Hangzhou Hanray Industry Co., Ltd , https://www.airsuspensionride.com
In the Eastern Alps of Europe, there are three selection plants, Leibu, Blebe, and Mezica, which use pre-selection of heavy medium, pre-selection of jigging and pre-selection of heavy medium and jigging. The situation can be used for reference.
Geological structure of Leibniz Italy, Austria and Yugoslavia Brian Baker Mei Ji card three belong to the Alpine Triassic deposits, the main component of metal minerals are galena and sphalerite, in addition there are different levels of time Raw minerals such as leucite, lead sulphate, smithsonite and hydrozincite. The main gangue of Blabeck and Mezica is calcite , which is dolomite. Associated components are fluorite , barite and quartz . The raw ore metal content is shown in the table below.
The Mezica plant obtained coarse-grain concentrates before grinding, and at the same time, coarse-grained gangues were also separated. After the raw ore is coarsely crushed, the coarse gangue is first separated in the heavy medium sorting device. The enriched heavy products are ground, sent to the jigging process, and the coarse-grain concentrate is obtained, and the tailings are finely ground and then floated. [next]
In addition, Poland has studied the use of a narrow chute for pre-selection of ultra-fine-grain lead-zinc ore in the Orkuz mining area, and the effect is not bad.
The practice of lead and zinc dressing in Poland shows that there are free galena particles in the fraction of less than 1 mm. Usually the ore is broken down to below 0.2 mm for flotation. In addition, the squeezing method is used to sort out concentrates from less than 10 mm in size to prevent galena from being crushed. However, due to the too wide grain size of the selected materials, the efficiency of the jig selection is not high, and the fine-grained galena into the light products forms over-grinding, which brings difficulties to the flotation operation and easily causes the galena in the tailings. Loss. The sorting operation in the grinding-grading circuit avoids the loss of valuable minerals. However, due to the large yield of 0 to 1 mm, it is impossible to use a shaker or a jig. W. Blaschke and E. Malysa explored the feasibility test using a tapered chute.
The parameters that affect the sorting of the chute are:
(1) Pre-selection of materials No pre-selection classification is required. When there is clay , the 0.04 mm fraction is removed and de-sludged.
(2) Particle size and specific gravity difference The particle size is less than 4 mm, and the difference in specific gravity of the sorted mineral is not less than 1 g/cm 3 . When the ratio of the specific gravity of the two minerals is greater than 1.7, the sorting conditions are optimal.
(3) The feed concentration is generally in the range of 45 to 60% (weight percent concentration).
(4) Chute size Suitable length is between 0.9 and 1.2 m; the opening angle of the groove wall is 8 to 12°.
(5) Inclination angle of the groove The inclination angle must be greater than the critical angle of 1 to 2° when the particles begin to deposit on the bottom of the groove.
(6) Efficiency Practice has shown that the optimum treatment capacity for a single tank is 0.6 to 1.5 tons per hour.
The process of reselecting the preselection is shown in the figure below. 
Pre-sorting using a tapered chute can reduce the ore dressing cost of re-election processing of 1 to 0 mm, and the number of shakers is reduced to the original -
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