The slurry adjustment before flotation is an important operation in the flotation process, including the determination of the concentration of the slurry and the selection of the mode of slurry adjustment.
I. The method of expressing the concentration of the slurry and the determination of the concentration of the slurry refer to the content of solid ore in the slurry. There are two ways to express the concentration of the slurry: the percentage of solid content and the ratio of liquid to solid. The percentage (%) of solids content represents the percentage of solid mass (or volume) in the slurry, indicated by the symbol R, sometimes referred to as the percent concentration. The common flotation concentrations in flotation plants are listed in Table 1.
Table 1 Common pulp concentration in flotation plants
| Ore type | Flotation cycle | Mortar concentration /% solid | |||
| Rough selection | Featured | ||||
| range | average | range | average | ||
| Copper sulfide ore | Copper and iron sulfide | 22~60 | 41 | 10~30 | 20 |
| Lead-zinc sulphide ore | lead | 30~48 | 39 | 10~30 | 20 |
| Zinc | 20~30 | 25 | 10~25 | 18 | |
| Molybdenum sulfide ore | Molybdenite | 40~48 | 44 | 16~20 | 18 |
| iron ore | Hematite | 22~38 | 30 | 10~22 | 16 |
The methods for determining the concentration of pulp are divided into two types: manual measurement and automatic control. At present, most domestic mineral processing plant has made a lot of valuable experience in the research and promotion of the concentration of automatic control, it laid the foundation for the production of stable use in the future. The problem is that the sensitivity is not enough, the adjustment control value is unstable, and the like. However, whether it is a concentrator with automatic control equipment installed or a concentrator without automatic control, manual measurement of concentration is still indispensable. Manual measurement, generally using the concentration pot method, under the premise of the known concentration of pot volume, self-weight P and ore density, the relative G value can be calculated according to different R values, and the concentration conversion table is placed on the production site. The operator can quickly find the corresponding slurry concentration from the conversion table based on the G value obtained by weighing.
II. Influence of slurry concentration on flotation Pulp concentration is one of the important process factors in the flotation process, which affects the following technical and economic indicators.
(1) Recovery rate. In the flotation of various minerals, the concentration of pulp and the recovery rate have obvious regularity. When the slurry is very thin, the recovery rate is low. As the concentration of the slurry increases, the recovery rate also increases gradually and reaches a maximum. However, after the optimum pulp concentration is exceeded, the recovery rate is lowered. This is because the concentration of the slurry is too high or too low, which will deteriorate the aeration condition of the flotation machine.
(2) Concentrate quality. The general rule is that the quality of the concentrate is higher when the flotation is carried out in the leaner slurry, and the quality of the concentrate is decreased when the flotation is carried out in the thicker slurry.
(3) dosage of the drug. In the flotation, a certain concentration of the agent must be maintained in the slurry in order to obtain a good flotation index. When the concentration of the slurry is high, the amount of the agent in the liquid phase increases, and the amount of the treatment per ton of ore can be reduced. Conversely, when the concentration of the slurry is low, the amount of the treatment per ton of ore increases.
(4) The production capacity of the flotation machine. As the concentration of the slurry increases, the production capacity of the flotation machine by the throughput is also increased.
(5) Flotation time. When the concentration of the slurry is high, the flotation time will increase, which will help to improve the recovery rate and increase the productivity of the flotation machine.
(6) Water and electricity consumption. The higher the concentration of pulp, the less water and electricity consumption per ton of ore will be treated. In the actual production process, in addition to maintaining the optimum slurry concentration during flotation, the ore properties and specific flotation conditions must be considered. The general principle is: minerals with high flotation density and coarse grain size tend to use higher pulp concentration; when flotation density is small, fine grain size or slime, lower pulp concentration is used; roughing operation is higher The concentration of the slurry can guarantee high recovery and save the pharmacy. Selecting a lower concentration will help to improve the concentrate grade. The concentration of the sweeping operation is affected by the rough selection operation and is generally not controlled separately.
Third, the concept of grading and mixing and application of slurry is to mix the ore into a suitable concentration of pulp, and then add the flotation agent, and stir and mix, so as to ensure that the flotation process is carried out normally and effectively. The grading and tempering is to adjust the pulping conditions according to different particle sizes, and the pulp is classified into two or three branches according to the coarse and fine granules for pulping. The granularity limit of the classification can be determined by experimentation. The grading and pulverizing is divided into two pulverizing schemes. The medicinal agent is only added to the ore (the coarser grain size) part. After the ore is pulverized, the slime is partially incorporated into the ore and floated together with it. This kind of scheme is suitable for the flotation activity of the slime is higher than that of the ore, while the coarser granularity needs to increase the dosage or supplement the other strong collector , so that the treatment can make the difference of the floatability of the coarse and fine particles. Smaller and tend to be uniform. In addition, the coarser particles require a higher concentration of the drug, which is also achieved by fractional slurrying. 'The experience of graded pulping of lead-zinc mine proves that the concentration of xanthate in the coarse fraction is 7-10 times of the average value of general pulping. The advantage is to ensure effective flotation and improve selectivity. There are three plans for pulping. The slurry is divided into three grades: ore I (coarse grain), ore sand II (middle grain) and slime III. The medium-grain grade generally has good buoyancy, while the coarse-grained and slime require special pulping. When the difference in floatability of the three branches is large, this scheme is adopted, but there are many equipments and pipes. Therefore, in general, it is relatively simple to use two pulps.
Hydraulic Support System Seals Kits
Hydraulic Support System Seals Kits
Hydraulic sealing equipment widely used in mine engineering and support system in tunnels
Mining hydraulic support sealing kit
Design description
The piston combined seal consists of a sealing ring, an elastomer and two retaining rings.
The sealing ring plays a sealing role, and the material is high-performance water-resistant polyurethane;
Elastomer provides elastic preload and wear compensation, and the material is NBR;
The retaining ring plays a protective role against extrusion,
The material is polyformaldehyde (POM).
Operating conditions
Maximum pressure: 70MPa,
Maximum speed: 0.3m/s
Temperature range: - 35 ° C~+110C
Working medium: 5% emulsion (HFA)
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