As an important non-ferrous metal, lead and zinc are widely used in national economic construction. With the development of industry, the demand for lead-zinc concentrate raw materials has increased. In order to increase the production of lead-zinc raw materials, the concentrator must choose a suitable lead-zinc ore beneficiation process. The separation of lead-zinc ore is mainly flotation, and its beneficiation process can generally be divided into four parts, namely: crushing and screening stage, grinding stage, separation stage and dehydration and concentration stage. The following are the detailed beneficiation process of lead-zinc ore.
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The three processes often used in the crushing stage of lead-zinc ore are: two-stage one-closed-circuit crushing, three-stage open-circuit crushing and three-stage one-closed-circuit crushing. Xinhai Mining will refer to the factors such as the largest lump of raw ore, physical and chemical properties of raw ore, ore mud content and required final ore particle size when formulating the crushing process for customers. Its crushing operation includes two basic operations of crushing and screening. The screening stage of lead-zinc ore can be divided into pre-screening and inspection screening. The pre-screening is set before the crushing operation, and the fine-grained lead-zinc ore is pre-screened and entered into the grinding operation to avoid over-grinding. At the same time, pre-screening can improve the working efficiency of crushers used for primary crushing operations. Due to the different sizes of the ore discharged products of the crusher, in order to meet the particle size requirements of the final crushed product, screening equipment is usually set up for inspection and screening after the crushing operation. In order to improve the recovery rate of concentrate, when designing the crushing process, inspection and screening will form a closed circuit with the last stage crusher. If the raw ore of lead-zinc ore contains a lot of water or mud, it is necessary to wash the ore to avoid clogging the crushing equipment, resulting in low equipment operation efficiency and affecting the efficiency of lead-zinc ore beneficiation.
The lead-zinc ore grinding stage can be divided into one-stage grinding process and two-stage grinding process. When the required grinding particle size is greater than or equal to 0.15mm, a single-stage grinding process can be selected for small and medium-sized concentrators, and two-stage grinding processes can be selected for large-scale concentrators. The grinding stage of the lead-zinc ore needs to be followed by a grading operation. In order to improve the efficiency of grinding operations, the concentrator can carry out pre-classification, inspection classification and control classification. During pre-classification, the qualified particle size of lead-zinc ore should not be less than 14%-15%, and the maximum particle size should be ≤6-7mm. The function of inspection and classification is to ensure that the size of the overflow pulp is qualified, and the unqualified coarse particles are returned to the grinding. Grinding operations often form a closed circuit with grading operations.
During the flotation of lead-zinc ore, it can be divided into preferential flotation process, mixed flotation process, partial mixed preferential flotation process and equal flotation process according to the different flotation sequence.
①Preferential flotation process: During preferential flotation, one of the minerals is selected first, and the rest of the minerals are inhibited and not flotated. After that, the remaining minerals are activated and then enter the next stage of flotation for sorting. The specific process is as follows: the lead-zinc raw ore is pretreated and then enters the flotation machine, the lead concentrate is flotated first, and then the remaining minerals enter the second-stage flotation machine for second-stage flotation to obtain zinc concentrate. The remaining minerals can also be floated again.
②Mixed flotation process: Mixed flotation is to flotate two or more useful minerals together, and the obtained mixed concentrate is then separated, and finally several qualified concentrates are obtained, namely: lead and zinc ore after grinding Then it enters the flotation machine for mixed flotation, and the tailings are discarded. Lead and zinc concentrates can be obtained by separating lead-zinc mixed concentrates.
③Partial mixed preferential flotation process: This process is to flotate some two kinds of useful minerals in lead-zinc ore, while suppressing the remaining minerals. The mixed concentrate is separated and the third useful mineral in the ore is activated by flotation. For example, when the copper-lead-zinc ore adopts partial mixed preferential flotation, the copper-lead mixed concentrate is preferentially floated, and then copper and lead separation and zinc activation flotation are carried out respectively.
④Equal flotation process: It is mainly based on the difference in flotation of useful minerals, and flotation is carried out first easy and then difficult. That is, the lead-zinc ore enters the flotation machine to firstly conduct flotation of lead-based lead-zinc ore, and then gradually separate lead and zinc to finally obtain lead concentrate and zinc concentrate.
In order to meet the standard of concentrate, the lead and zinc concentrates after flotation need to be dewatered and concentrated. A thickener can be used for concentration, and a filter or a filter press can be used in the concentrator for dehydration. The specific model can be determined according to the mineral processing budget and process design.
The above is the process flow of lead-zinc ore beneficiation. Because lead-zinc ore has complex components and various types, its beneficiation process must be formulated according to the results of ore analysis and test. Xinhai Mining, as the initiator and practitioner of "Mining Whole Industry Chain Service (EPC+M+O)", can provide you with lead-zinc beneficiation tests, customized beneficiation solutions and efficient beneficiation equipment, such as If necessary, welcome to consult Xinhai Mining.