Methods to improve the pretreatment of specific gold ore dressing

To optimize the pretreatment process of specific gold ore dressing, it is necessary to comprehensively consider factors such as gold ore characteristics, processing costs, and environmental protection requirements. In actual operation, we can start from detailed analysis of gold ore properties, test and screen suitable processes, improve existing processes, introduce joint pretreatment, etc., to improve the adaptability of pretreatment processes to specific gold ore, thereby improving the extraction efficiency of gold.

Detailed analysis of gold ore properties

Determine the content of various elements in gold ore through chemical analysis, clarify the gold grade and the content of associated elements such as arsenic, sulfur, and carbon. Use microscopic observation, electron probe analysis and other methods to study the embedding characteristics, particle size and shape of gold minerals, as well as the symbiotic relationship with other minerals. For example, if gold is wrapped in sulfide minerals in the form of fine particles, the pretreatment process needs to focus on how to destroy the sulfide mineral structure to expose the gold. It is also necessary to determine the type and content of carbonaceous materials, because different types of carbonaceous materials have different effects on gold leaching. For example, organic carbon may affect gold leaching through chemical adsorption, while graphite carbon mainly affects through physical adsorption.

Screening suitable processes through experiments

Small-scale tests of different pretreatment processes are carried out on gold ores of certain properties, such as roasting, chemical oxidation, and biological oxidation tests, to compare the gold leaching rate, impurity removal effect and other indicators of gold ores after treatment with different processes. In the roasting test, the roasting temperature, time and other parameters are changed to observe the changes in the gold leaching rate; in the chemical oxidation test, different oxidants and their dosages are tried to determine the optimal reaction conditions. According to the results of the small-scale test, the process with better adaptability to the gold mine is selected for further optimization. If the gold leaching rate is high when sodium hypochlorite is used as an oxidant in the chemical oxidation test of a gold mine, the process can be optimized around the use of sodium hypochlorite in the future.

Improving existing processes

For the selected pretreatment process, targeted improvements are made according to the characteristics of the gold mine. In the roasting process, if the gold mine contains a high sulfur content, oxygen-enriched roasting or two-stage roasting technology can be used. Oxygen-enriched roasting can increase the roasting speed and efficiency and reduce harmful gas emissions; two-stage roasting can first remove part of the sulfur at low temperature, and then roast at high temperature to fully expose the gold. In the chemical oxidation process, special oxidizing agents are developed for specific impurities in gold mines. If the gold mine contains high arsenic, agents that can preferentially oxidize arsenic without affecting gold leaching can be developed to improve the leaching effect of gold.

Introduction of combined pretreatment process

Depending on the complexity of the gold mine, two or more pretreatment processes are used in combination. For gold mines containing carbon and sulfides, a flotation-roasting combined process can be used. First, some carbonaceous materials are removed by flotation to reduce the impact of carbon on subsequent processes, and then roasting treatment is carried out to oxidize sulfides and fully expose gold. A biological-chemical oxidation combined process can also be used, first using biological oxidation to decompose some sulfides, and then further treated with chemical oxidation to increase the leaching rate of gold.

The above are several methods to improve the pretreatment effect of specific gold mines. In actual production, the beneficiation or pretreatment operations for specific gold mines need to be determined according to the properties of the ore. It is recommended to conduct beneficiation tests first, and through experimental analysis, design a suitable process plan to improve the final recovery rate of gold.