滤材沉积法回收贫液中载金粉炭试验研究.

A gold mine in Inner Mongolia produces about 73 t solid waste annually that runs up the leaching heap with barren solution, of which about 40 t is powdered carbon with a gold loading of 373 g per ton. While gold is lost along with the powdered carbon, some gold is also captured by the powdered carbon during heap leaching. The filter bags arranged in a pipeline layout are not satisfactory. In this study, the filter material deposition method was employed to collect the powdered carbon from the barren solution. The filter material was folded into a certain shape and placed in a barren solution tank for the natural deposition of the carbon. 3 types of filter materials were selected based on the properties of the powered carbon and barren solution, and surface roughness tests were conducted. The effects of different filter materials on the powered carbon deposition were compared through experiments, and it was found that the deposition capacity was positively correlated with the surface roughness of the filter material. The deposition rate was determined through kinetic experiments, showing an initial increase and then a decrease over time. The deposition capacity was affcted by the filter material pore size, with the best performance observed when the pore size was 1.5 times the powdered carbon particle size D80. A combined gas-water desorption method was used to recover the deposited powered carbon. The results showed that the deposition of 20 µm polypropylene non-woven filter material for 16 h yie- lded the best performance, with a unit area deposition amount of 79.31 g/m². About 40% of the powered carbon con tent can be captured when the barren solution passes through the deposition unit, and the desorption rate reaches 88.7%. The overall recovery rate was 35.5%. The filter material also exhibited good reusability after desorption. The research findings have certain reference significance for heap leaching processes that use activated carbon as an adsor- bent. [ABSTRACT FROM AUTHOR]