Sustainable Mining and Metallurgy

Abstract:This paper analyzed the current situation of carbon emission in nonferrous metal industry, pointed out that carbon emission mainly occurred in smelting process, especially in aluminum smelting process, and put forward three main ways to realize carbon neutralization: using clean energy, improving energy utilization rate and developing CCUS technology. Among them, hydrogen energy was the preferred clean energy for nonferrous metal industry; The improvement of energy utilization can be achieved by developing new processes and eliminating backward processes, improving the design and manufacturing level of key equipment, and developing thermal energy cascade utilization technology. The nonferrous metal industry should intensify its layout to ensure that carbon neutrality targets at all stages were achieved on schedule.

Abstract:This paper introduced the current situation of restoration and treatment of abandoned mines by local governments, the main contents of mine restoration work, a variety of “mine ecological restoration+” models, and the problems faced by abandoned mine governance. It showed that local governments should adopt systematic thinking to combine ecological restoration of abandoned mines with land development, industry imports and rural revitalization, and explore a road that conforms to local characteristics in terms of restoration technology, restoration mode, capital allocation and comprehensive development and utilization.

Abstract:The construction of project cost index system was the work of summarizing the previous data to achieve the purpose of guiding future work. This paper introduced the types and data sources of project cost index system, and put forward the compilation method and content of project cost index system. The project cost index system should be compiled according to the hierarchical structure of “construction project-regional project-single project-unit project-subentry project”. The specific contents included engineering overview, construction cost index, equipment price index, single project cost index, etc. The cost index system should be updated and maintained by means of information technology.

Abstract:This paper introduced the practice of removing oil from the residual liquid/stripping liquid and recovering the extracted organic phase in the extraction metallurgy process of an enterprise. The oil removal rates of the designed modified material deoilers in three cascaded extraction systems were 78.79%, 19.10% and 16.42%, respectively，and the oil content of the solution after oil removal was more than 10mg/L, which cannot meet the design requirements. By analyzing the principle of oil removal, a combined device of dissolved air pump and air flotation clarification box were added at the front of the oil remover, and a activated carbon adsorption tank was added at the end of the oil remover. After three times of oil removal, the oil removal rate reached 98.69%, 95.11% and 95.17%, respectively，and the average oil content of the solution was less than 10mg/L, and the recovery rate of the extraction organic phase reached more than 60%. The effect of removing oil and recovering extractant was better.

Abstract:According to the characteristics of platinum-palladium concentrate in a copper smelting enterprise, the palladium purification process was designed as “ore washing→acid leaching→chlorination leaching→sodium sulfite reduction gold→platinum and palladium precipitation→platinum and palladium separation→palladium reduction ”, and the platinum purification process was designed as “ammonium chloroplatinate reduction→chlorination leaching→platinum precipitation by ammonium chloride→calcination”. The selection of purification equipment and industrial design were made, the economic benefits were briefly analyzed. The results showed that the recovery rates of platinum and palladium were more than 95.0% and 98.5%, respectively. The process can recover 12.0kg platinum powder and 107.6kg palladium powder per year, the annual increase income was 61.58 million yuan, and the annual investment cost was about 0.67 million yuan. The economic benefit of the project was remarkable.

Abstract:Lead anode mud was an intermediate product obtained by crude lead electrolytic refining, which contained a large number of valued accessory elements that can be further extracted, such as gold, silver, lead and other elements. Based on the actual production, the wet pretreatment process of lead anode slime was studied in this paper. The lead anode slime was oxidized by hydrogen peroxide, and the optimum oxidation prepreg conditions were determined. The results showed that under the conditions of hydrogen peroxide dosage of 40g, hydrochloric acid concentration of 4.5mol/L, liquid-solid ratio of 6∶1, leaching time of 3h, and leaching temperature of 80℃, the oxidation pre-leaching effect of lead anode slime was good, the leaching rate of Bi and Sb could reach more than 98%, and the leaching rate of As and Cu reached more than 90%, the concentration of Au in leaching solution below 0.1mg/L, the leaching concentration of Ag was less than 30mg/L, and the slag rate was reduced to less than 25%. The process was simple and low cost, which provided a new way for the treatment of lead anode mud.

Abstract:Since reaching the production standard in 2014, the 300000 tons copper electrdysis system in the electrolytic workshop of a companys smelter had faced the problem of increasing production capacity without increasing equipment and facilities. By improving the operation efficiency, increasing the current density and repairing the stainless steel cathode plate and other process measures. The cathode copper production capacity was increased about 12.6% compared with the design capacity, and good economic benefits were achieved.

Abstract:The three-dimensional simulation model of flue gas fluid in Ausmelt furnace flue was established by finite element simulation to study the flow of flue gas in the flue. The simulation model was compared with the actual coking situation of the flue during the overhaul of the Ausmelt furnace. The comparison results showed that the flue gas velocity and flue gas temperature of the three-dimensional simulation were consistent with the flue coking, so the simulation model was reliable. According to the simulation results and fluid mechanics principle, the left flue, the horizontal flue and the lower ash hopper were optimized, and the simulation prediction was carried out again. The results showed that the negative pressure of flue gas was basically unchanged, and the maximum flow velocity and outlet flow velocity of flue gas increased by 35.7% and 115.7%, respectively. The central flue gas temperature was still above 1000℃, and the outlet flue gas temperature was increased to more than 2.5 times. Therefore, after flue optimization, the coking problem would be greatly improved, but there would be more faults in the subsequent electrostatic precipitator system. It was necessary to adjust the subsequent process parameters to cooperate with the optimization to achieve the desired effect.

Abstract:According to the relevant national standards and international standards of roads lighting, and combined with the actual working condition of factory road, this article studied and analyzed the selection of evaluation indicators of road lighting in industrial projects. The uniformity, longitudinal uniformity, surround ratio and dazzle should be determined according to the CIE standard. The standard values of the average brightness and average illuminance of the pavement can be determined according to the national standards. Then, combined with practical engineering experience, DIALUX software was used for simulation calculation, the selection of road lighting lamps, light sources and lamp layout in the actual design were proposed.

Abstract:Aiming at the problems of many calculation formulas, complicated calculation in traditional generator selection, the application of ETAP software in generator selection was discussed. Taking the actual project with the total capacity of 679.89kVA and the maximum capacity of 160kW for a single load as an example, the generators with capacity of 800kVA, 1000kVA and 1250kVA were selected to test. The start-up of the motor was simulated by ETAP software, and the generator selection was determined according to the changes of motor current, voltage and generator bus voltage. The results showed that when the generator capacity was 1250kVA, the maximum power motor start would not cause other emergency equipment power loss, and the start time was shortest, motor terminal voltage change was minimal. Compared with the traditional selection calculation method, the selection of generators by ETAP software can simplify the design work and improve the work efficiency, which provided a new method for the scientific selection of generators.

Abstract:In this paper, the principle of drying wet materials by microwave dryer and the properties of arsenic trioxide were studied to demonstrate the feasibility of microwave dryer drying arsenic trioxide. By introducing the overall structure of the microwave dryer, the advantages and disadvantages of the microwave dryer in the production of arsenic trioxide were expounded, and the operation parameters and drying effect of the microwave dryer were explored through trial production. The trial production showed that the arsenic trioxide microwave dryer had the characteristics of high quality, high efficiency, energy saving and environmental protection, and the production effect was good.

Abstract:The working principle of aluminum hydroxide slurry hydrocyclone was introduced, and the energy-saving technical transformation was carried out according to the actual production situation of alumina production line in an aluminum company, such as long service life, serious scarring, poor classification effect and large power consumption. After design and selection calculation, various parameters of the hydrocyclone were determined. A group of aluminum hydroxide slurry hydrocyclone with processing capacity of 600m³/h was selected to replace the original two groups, and the new hydrocyclone was reasonably optimized. The seed decomposition process was simplified by removing unnecessary power consumption equipment. After process optimization, the cost can be saved about 1.885 million yuan per year, and the efficient classification of aluminum hydroxide slurry can be realized.

Abstract:After investigating a large number of photovoltaic power plants, it can be seen that the crystal silicon components were prone to problems such as black core, black spot, black mass, hidden crack and crack. Two main reasons for common problems of components were the poor quality of raw materials and the problems of production preparation process，and non-standard operation of construction personnel in construction installation. In order to ensure the quality of crystalline silicon components and the stable operation of power station, the quality of solar crystalline silicon components should be scientifically managed from the aspects of production, manufacturing and construction. Not only the production and manufacturing process of components should be strictly controlled, but also the components handover, components storage, construction and installation of power station construction should be strictly implemented in accordance with the specifications.

Abstract:Taking a polymetallic ore concentration plant in Inner Mongolia as an example,aiming at the influence of severe cold weather on beneficiation, this paper introduced in detail a number of energy-saving measures to adapt to the climatic characteristics of severe cold region, such as centralized layout of multi-work workshops, good building orientation, SAB process, closed-circuit classification formed by high frequency fine screen and ball mill, multi-layer layout of shaking table, selection of wear-resistant pipe, pipeline anti-freezing, adopting water returning near concentrator, and reducing heating temperature gradient. The energy-saving measures provided reference for construction of concentrator in severe cold region and cold region.

Abstract:Combining with the characteristics of upstream tailings ponds, the common problems in the operation of upstream tailings pond and the corresponding treatment measures were analyzed. Taking the closure treatment of a tailings pond as an example, it was shown that the most basic treatment measures for the closure treatment of tailings pond should include the treatment measures of tailings dam, flood drainage system and monitoring facilities, and targeted management should be carried out according to the specific situation of the tailings pond, so as to achieve long-term stability after the closure of tailings pond.

Abstract:In view of the problem that the collected flue gas and process flue gas of a heavy metal smelting plant cannot reach the emission standard after treatment, and the wastewater treatment cannot achieve zero discharge, the optimization scheme of collected flue gas treatment, process flue gas treatment and wastewater treatment were proposed. The environmental flue gas treatment process had been reformed by adding and improving the flue gas capture cover and reasonably adjusting the air volume at each pumping point. One dynamic wave washing system, one ionic liquid absorption system and one emergency desulfurization tower system were added to the process flue gas treatment process. Wastewater treatment process was newly built. Through the optimization of environmental protection facilities, the emission standards of air pollutants ρ (particulate matter)＜10mg/m³ and ρ (SO₂)＜100mg/m³ were achieved, and the wastewater was zero discharged.

Abstract:Through the analysis of two faults in the air separation facility, the serious consequences and harmfulness of water entering the air separation facility were revealed. In this paper, the whole process of troubleshooting and analysis was discussed in detail. Finally, the cause of the liquid flood accident was found to be the leakage of the heat exchange tube of the air cooler of the supercharged expander, and the water entered the air separation device, resulting in the blockage of the high pressure air channel of the plate heat exchanger, which made the heat transfer capacity of the plate heat exchanger seriously insufficient. According to the fault reasons, reasonable suggestions and preventive measures were put forward for the safe operation of air cooler of supercharged expander.