The treatment of amalgam includes three main steps of washing, pressure filtration and distillation. After treatment amalgam, mercury King and ultimately obtained sponge. After melting the sponge obtained gold silver gold alloy ingot, which is sent to the bank or sell refinery refining. The recovered mercury returns to the amalgamation operation.
1. Washing of mercury paste
Mercury paste collected from amalgamation equipment, such as mercury amalgamation, amalgamation chute, thorium mining machine and amalgamation tank, can be sent after washing to remove heavy sand, gangue and other impurities Pressure filtration.
The mercury paste scraped from the mercury-mixed plate is relatively pure and the treatment is relatively simple. Washing is carried out on the console. Operating table laying a thin copper plate, with a staple around the mesa 20-30mm high wood, to prevent the operation of the dispersed mercury spill onto the ground. A hole is drilled in the table, and mercury that flows during operation can flow through the hole to the mercury susceptor. The mercury paste scraped from the mercury plate is repeatedly washed in the porcelain plate and water is added. The operator puts on the rubber glove and continuously rubs the mercury paste with his hand to wash the impurities in the mercury paste to the utmost extent. Mixed amalgam in the scrap iron magnet can be used to suck out. In order to make the mercury paste soft and easy to wash, it can be diluted with mercury. Washing the mercury paste with hot water can also make the mercury paste soft and easy to wash, but it will accelerate the evaporation of mercury and endanger health. It is not advisable to use hot water to wash the mercury paste if the safety measures are not available. The mercury paste with high impurity content is dark gray. The washing operation should wash the mercury paste until it is bright and smooth, then wrap the mercury paste with a dense cloth and send it to the pressure filter.
Mercury pastes obtained from amalgamation cartridges and mercury traps contain large amounts of impurities such as heavy sand minerals and gangues, usually separated by short chutes or gold pans to separate the mercury paste from other heavy minerals. Mercury pastes produced in various mechanical washing and mixing amalgamation tubes, such as amalgamation plates and small cyclones, are more commonly used abroad. Figure 1 is a structural diagram of a sharp-bottom gold pan used in many gold mines in South Africa. The disc has a diameter of 900-1200 mm, the bottom of the disc is concave, and the circumference of the disc is 100 mm high. The rear of the disc is connected to the crank rod, and the front end of the disc is supported by the scroll. On the guide roller, through the bevel gear transmission, the disc is horizontally moved by the crank mechanism, and the mercury paste produced by the mercury-mixing cylinder is placed in the disc, and the mercury paste is applied due to the rotary motion of the disc and the flushing of the water flow. The gangue entrained in the middle is sent to the front end of the disc to be discharged through the chute, and the mercury paste having a large density (specific gravity) is collected in the center of the disc and discharged through the discharge port. Each 1200mm diameter tipping gold pan can handle 2-4t amalgamation cylinder products daily.
[next]
The structure of the heavy sand separation disc developed in China is similar to that of the sharp bottom gold pan. The diameter of the disc is 700mm, the height is 120mm, the working time is 1.5-2.0h, and the product of 60-120kg amalgamation can be processed at one time.
There is also a mercury paste separator in foreign countries. The structure is shown in Figure 2. The separated material is sent to the receiving hopper, and the coarse-grained gangue is removed through the screen. The fine-grained material passing through the screen falls into the front-end trap. Box, in this box, the material is flushed with water, so that the fine-grained gangue particles enter the terminal trap box through the stage grid, and the mercury paste is left in the front-end trap box and the grid, and is cleaned up by mechanical equipment. The amalgam is sent for washing, and the washing method is the same as the method of washing the mercury amalgam.
2. Pressure filtration of mercury paste
The washed mercury paste still contains a large amount of excess mercury, ie free mercury, which can be removed by pressure filtration. The washed amalgam is sent to a pressure filter with a dense canvas to remove excess mercury and to obtain a concentrated solid mercury paste (hard mercury paste). In small-scale production, manual pressure filtration is also used, and it can also be squeezed by a screw filter press or a lever filter press. Plants with large amounts of mercury paste work with pneumatic and hydraulic filter presses.
The structure of the screw filter press commonly used in gold mines is shown in Figure 3. The chassis is drilled with holes and can be removed. During operation, the wrapped mercury paste is placed on the chassis and fixed firmly with the cylinder. The hand wheel is rotated to push the screw to push the piston down to squeeze the mercury paste. The excess mercury in the mercury paste is extruded through the circular hole in the chassis. It flows out and collects in a container at the lower part of the filter press. The hard mercury paste can be removed by removing the chassis. [next]
The solid mercury paste produced by pressure filtration contains 20%~50% of gold, and its gold content mainly depends on the size of the amalgamated gold particles. When the gold particles are larger, the gold content is as high as 45% to 50%, and the gold content is reduced to 20% to 25%. In addition, the gold content of the hard amalgam is also related to the pressure of the filter press and the density of the filter cloth.
Mercury recovered by mercury paste filtration often contains 0.1% to 0.2% gold and can be returned for amalgamation. The gold recovery capacity of recovered mercury is higher than that of pure mercury. Especially when the mercury amalgamation plate fails, it is better to use the mercury recovered by mercury paste pressure filtration. When the mercury-mixed gold particles are extremely fine and the filter cloth is not dense, the gold content in the recovered mercury is high, so that after the mercury is recovered for a long time, the gold will precipitate and sink to the bottom of the container.
Pipe Extrusion Equipment,Eva Pipe Extrusion Equipment,Evoh Pipe Extrusion Equipment,Mpp Pipe Extrusion Equipment
Zhejiang Jinhai Plastic Machinery Co., Ltd. , https://www.jinhaiextruder.com