NOUFERROUS METALLURGICAL EQUIPMENT

Abstract:China's lead ore resources are characterized by “more poor ore and less rich ore”, and the excess supply of overseas lead concentrate has decreased. The lead smelting process is characterized by the coexistence of multiple element resources, large fluctuations in raw material quality, and complex smelting processes. Currently, China's non-ferrous metal smelting industry is in a state of mechanization, electrification, automation, and informatization, and the development of different enterprises is unbalanced. Based on the above, this article introduces the distribution of lead ore resources (lead concentrate and lead-containing waste) and the main uses of lead, the development process of lead smelting technology, and provides a detailed overview of the current main lead based material smelting technologies, such as oxygen bottom blowing smelting-melt reduction-oxygen rich volatilization refining technology, oxygen rich immersion top blowing smelting technology, lead sulfate slag wet smelting technology, side-submerged combustion melting pool smelting treatment technology for regenerated lead resources, brittle sulfur lead antimony ore treatment technology, lead anode mud treatment technology, copper floating slag and lead concentrate slag treatment technology, lead electrolysis technology, etc. Combining with the industrial production scenario of lead smelting, deep learning methods are used to establish a data-driven model of the smelting furnace, which can achieve real-time prediction and evaluation of key operating indicators of the system and promote the intelligence and digitization of lead smelting technology, to meet the development opportunities and challenges of the lead industry.

Abstract:Non-ferrous metal is an important material basis for national economic development, and the lead-based solid waste generated from its production process is both resource and pollutant, which can provide resources for economic development when properly disposed，and on the contrary, would cause a certain amount of pollution to the environment.This paper analyzes the source of lead-based solid waste, resource and environmental attributes, production, regional distribution, future production changes, etc.The results show that in 2022, China's non-ferrous metal smelting of lead-based solid waste production was 1152 million tons, and it is expected that the production of lead-based solid waste in 2024 will peak at 1216 million tons, and fall to 111 million tons in 2030, the lead-based solid waste is mainly located in Henan, Anhui, Yunnan, Hunan and Guangxi,which together account for nearly 60%. Combined with the technical characteristics of lead-based solid waste disposal, suggestions on lead-based solid waste and industrial layout are put forward, such as improving policies and regulations, improving the level of technology research and development and synergistic disposal.

Abstract:Based on the analysis of the characteristics, composition and physical properties of lead-based solid waste, the reaction mechanism of primary ore smelting with lead-based solid waste under the conditions of bottom blow oxidation smelting, direct reduction of pulverized coal by bottom blowing and fuming is expounded. The process indexes of primary ore smelting with multi-form lead-based solid waste under the hot state test are listed. The process operation indexes and the engineering application effect on refractory life, lead content in reduction slag, production cost, waste slag, waste gas and waste water after application of demonstration project are summarized. The annual treatment of lead-based solid waste in the demonstration project can reach 270,000 tons, which reflects the superiority of the primary mine cooperating with multi-form lead-based solid waste smelting technology and large-scale equipment.

Abstract:By analyzing the elemental composition and phase composition of typical lead-based solid waste, a collaborative treatment scheme of primary lead concentrate and lead-based solid waste was proposed. The proportion of primary lead concentrate and lead-based solid waste in the collaborative treatment process was determined by the industrial experiment. When the lead paste 9.47%, the lead dust 16.93%, the leaching slag 8.4% and the lead glass 0.93% were added, the production system could realize self-heating and the lead content in the reducing slag was less than 2%. Based on this technology, the large-scale oxygen bottom blow melting, bottom blow reduction and fume volatilization production system of reduction slag can process 750000 tons of lead-containing materials annually, and the maximum amount of lead-based solid waste can reach 35.73%.

Abstract:This paper introduces the newly-built project of Henan Jinli Gold-Lead Co., Ltd.: demonstration of lead-based metal solid waste collaborative strengthening smelting industrialization and comprehensive utilization of zinc resources, especially the production practice of side-top blowing smelting technology to treat lead-based solid waste and other materials. This paper summarizes the production situation, expounds the main production technology, and lists the main production data and technical and economic indicators. Domestic zinc smelting is mainly based on wet smelting, and lead-containing zinc slag will be produced in its production process. In the past, due to backward technology, the slag was mainly stored in storage. In recent years, due to environmental problems, the solid waste must be treated. Therefore, various methods of miniaturization treatment of the solid waste residue have emerged. Because there are few valuable metals in the solid waste residue and the treatment cost is high, it is not economical to treat it alone. However, the application of side-top blowing smelting technology has solved the problems of environmental pollution caused by long-term storage of lead-containing zinc slag produced by zinc hydrometallurgy in the past, or high cost and uneconomical feature caused by miniaturization. Practice has proved that the side-top blowing smelting technology is feasible and has obvious advantages in treating lead-based solid waste, zinc smelting slag and other materials, and realizes the comprehensive utilization of solid waste resources. Moreover, the technology has advanced technology and low cost. Through production practice, it is proved that the technology can realize large-scale production.

Abstract:Under the dual pressure of supply and demand for lead, current recycled lead enterprises urgently need advanced and mature technology and equipment. The oxygen-enriched side-blown melt-pool smelting process for treating lead paste has been adopted by most newly built recycled lead plants in China. Among them, the side-submerged combustion smelting technology has been successfully applied in the smelting of metals such as zinc, lead, antimony, copper, and solid waste disposal. Through comprehensive research and analysis of the chemical reaction, operation system, furnace partition, furnace structure, spray gun and DCS system of the side-submerged combustion smelting process for treating lead paste, it is pointed out that the technology and equipment have the advantages of high melting strength, low energy consumption, safety and reliability, and good environmental protection effect after comparing with Vanukov Furnace technology. Its application prospect is optimistic, and it plays a positive role in promoting the improvement of China's regenerated lead smelting technology level.

Abstract:The jarosite slag produced in the process of zinc hydrometallurgy is harmful to human health and ecological environment, and will lead to waste of valuable metals. Therefore, it is imperative to treat and recover jarosite slag. Based on analysis of the composition and phase change of the raw jarosite slag, the optimum technological conditions and phase change law of Zn recovery from jarosite slag by melting and fuming based on carbothermal reduction method are discussed under the theoretical guidance of thermodynamic calculation. By calculation, the zinc phase in the jarosite slag is ultimately enriched in the form of zinc oxide (ZnO) in the fume; and the rationality of the theoretical calculation was verified based on the results of orthogonal experimental analysis. Considering reducing energy consumption, the experimental results were finally confirmed, and the optimum conditions for zinc recovery in the melting and fuming process of jarosite slag were as follows: reaction temperature 1200℃, holding time 100min, air flow rate 600mL/min and carbon ratio 30%, under these conditions, the recovery rate of zinc was 99.70%. The study provides a practical reference value for the recovery and utilization of zinc in jarosite slag.

Abstract:In view of the characteristics of industrial hazardous waste lead-silver slag produced by zinc hydrometallurgy in a Gansu zinc smelter, the side-submerged combustion smelting-continuous fuming process core equipment selection and engineering design for lead-silver slag were carried out, through the analysis of lead-silver slag smelting mechanism and the thermodynamic calculation of lead-silver slag smelted by side-submerged combustion smelting-continuous fuming process. An environmentally friendly, energy-saving, continuous and efficient lead-silver slag green smelting process and equipment have been developed, and a demonstration project for treating 140000 tons of lead-silver slag was formed. Through the engineering design and industrial practice of the side-submerged combustion smelting-continuous fuming process, the advantages of the side-submerged combustion smelting-continuous fuming process in the treatment of non-self-heating materials such as lead-silver slag are fully verified. By injecting coal into the molten bath in the form of pulverized coal and oxygen-enriched air smelting, precious metals such as silver has been recovered, and the side-submerged combustion smelting-continuous fuming process can effectively improve the fuel utilization rate and reduce the coal rate to ＜25%, which realized the reduction, harmlessness and resourceful utilization of zinc-containing hazardous waste lead-silver slag.

Abstract:China has abundant lead-zinc mineral resources, but the zinc hydrometallurgical process produces a large amount of lead-silver slag, which usually contains various valuable metals such as lead, silver, zinc, copper, antimony, and may also contain harmful elements such as arsenic and cadmium. At present, there is a lack of systematic research on the evolution law of the antimony phase in lead-silver slag during the side-blown melting-fuming process. The paper determines the existence form of antimony in lead-silver slag through thermodynamic theory calculations and reveals the evolution law of the antimony phase under different experimental conditions by investigating the effects of factors such as temperature, atmosphere, and time on the evolution of the antimony phase during the side-blown melting and fuming process of lead-silver slag. The optimal process for antimony recovery in the side-blown melting-fuming process of lead-silver slag is determined: the reaction temperature is 1290℃, the carbon ratio is 17.60%, and the holding time is 125min. Under these conditions, the antimony recovery rate can reach 82.54%.The study provides a reference for recovery of antimony from lead silver slag and resource utilization of lead-silver slag.

Abstract:Lead-silver slag produced by zinc hydrometallurgy will pollute the environment for a long time, so it is necessary to comprehensively recover valuable metals in lead-silver slag. Lead-silver slag produced in the process of comprehensive recovery hot acid leaching-jarosite method is treated by side blowing furnace melting + fuming furnace fuming process. The main process of the process includes two stages: melting of zinc leaching slag and reduction and volatilization of lead and zinc. In the melting process, the phase structure of lead-silver slag changes, the heavy metal ions wrapped can be released, the grade of valuable metals can be improved, and the sulfur content of molten residue can be reduced, which is beneficial to metal volatilization. Therefore, the lead-silver slag needs to be pretreated by desulfurization.In the paper, the research direction of desulfurization experiment of lead-silver slag is determined by the dominant zone diagram of Me-S-O system, and the effects of three factors, namely, volume ratio of nitrogen to oxygen, melting desulfurization time and melting desulfurization temperature, on desulfurization rate of lead-silver slag are investigated.The best technological conditions of melting desulfurization are as follows: nitrogen atmosphere, melting desulfurization time 40min, melting desulfurization temperature 1250℃, and the desulfurization rate is 98.17% under these conditions.The study has practical significance for comprehensive recovery of lead-silver slag desulfurization pretreatment process.

Abstract:The smelting slag produced by pyrometallurgy of copper concentrate is recovered by flotation, and the tailings contain Pb, Zn and Sb, which still have certain economic value for recovery. Comparative pilot tests were conducted on three typical pyrometallurgical recovery processes: direct reduction smelting, matte reduction smelting, and oxidation-reduction smelting.The results show the pyrometallurgical recovery process can achieve an ideal copper recovery rate, but different processes have different recovery effects on Pb, Zn and Sb; direct reduction smelting has improved the recovery rate of Pb; matte reduction smelting has improved the recovery rate of Zn; the smelting method requires a large amount of reducing agents and energy, and the economy needs to be carefully considered. The pyrometallurgical process is suitable for research as a backup process for copper recovery.

Abstract:The synergistic smelting process for lead-based solid waste with multiple metals is of great significance to achieving green treatment and efficient recovery, avoiding environmental pollution, and promoting carbon peaking and carbon neutrality. The efficient monitoring and intelligent warning system adopts the technology of integrating digital mechanism modelling and digital simulation modelling. Not only the complex mechanism model containing feed decomposition, element distribution and product coalescence is constructed, but also the three-dimensional production scene for continuous smelting process of lead-based solid waste is built. It intuitively and realistically displays the workshop building structure, production equipment attribute and dynamic production process, achieving digitalization and visualization of the entire smelting process. Moreover, through production data monitoring with the coupling analysis of mechanism models, as well as the warning analysis for equipment key parameter and on-site personnel safety, process personnel can understand any production details in real time, make more scientific and efficient decisions, and ensure the safe and stable operation of the production process.

Abstract:The bottom-blowing continuous treatment for lead-based solid waste has the characteristics of multivariability, nonlinearity, strong coupling and large lag, which cause difficulties for mechanism based modelling and optimization. To solve these problems, this paper proposes a data-driven raw material blending model for the smelting furnace, which achieves optimized control for key operating parameters. Firstly, based on laboratory and process historical data, the relationship between raw material composition and key process indicators of the smelting furnace is established by applying neural network; on this basis, the Particle Swarm Optimization algorithm is applied to solve the optimal ratio of each component in the raw material from the ideal operating conditions; finally, the ingredient problem is formulated as a multi-objective optimization problem with nonlinear constraints and then solved by SLSQP. Integrating the above modeling and optimization algorithms, a corresponding raw material management system has been developed.

Abstract:The heavy non-ferrous metal industry, especially the smelting industry of widely used heavy non-ferrous metals such as lead, zinc, and copper, is an industry of great international concern due to its heavy pollution. With the improvement of global environmental protection standards and the advancement of high-quality sustainable development strategies, heavy non-ferrous metal smelting enterprises, especially lead-zinc smelting enterprises, urgently need to innovate environmental protection technology and management measures to achieve the green upgrading of the industry and harmonious coexistence with the ecological environment. On this basis, some lead-zinc smelting enterprises have begun to seek external assistance to jointly carry out environmental protection management work, adopting the “Environmental Butler” model to solve daily management and emergency issues. The paper mainly analyzes the background of the birth of the “Environmental Butler” business, summarizes the model and service content of this business in combination with practical cases, and explores and looks forward to its future development direction.