Lead and zinc tailings recovery of silver, recovery of tungsten examples

First, the recovery of silver from lead zinc tailings

The storage of tailings in the Bajiazi lead-zinc ore dressing is more than 3 million tons, of which the silver content is relatively high, reaching 69.94g/t, which is re-ground to -0.053mm91.6% dissociated silver, using sodium carbonate as a regulator ( 3000g/t), butyl ammonium black drug (53g/t) and butyl xanthate (63g/t) as collector , No. 2 oil (8g/t) as foaming agent, silicone rubber (100g/t) for inhibition The agent is flotation of silver-containing concentrate with a grade of 1193.85g/t and a recovery rate of 63.74%. According to the tailings treatment capacity of 800t / d, the annual production days of 250 days, the annual recovery of silver 8.92t, the output value of about 2.23 million yuan.

2. Recovery of tungsten from lead-zinc tailings

The Baoshan lead-zinc-silver mine is a comprehensive deposit, and the ore processed by the concentrator comes from the primary ore body and the weathered ore body. The ore is mainly useful minerals brass ore, molybdenite, galena, sphalerite, bismuthinite, pyrite, scheelite, wolframite; major gangue minerals Grossular, Calcium iron garnet, quartz , calcite , pyroxene, amphibole, kaolin and the like. The plant's sulfide ore flotation tailings contain low-grade tungsten minerals, mainly scheelite. The tailings after primary ore flotation of lead and zinc contain 0.127% of WO3, of which scheelite accounts for 81%, black tungsten ore accounts for 16%, and tungsten carbide accounts for 3%. The grain size of scheelite is 80% concentrated in -0.074 mm + 0.037 mm; the grain size of the wolframite is 65% concentrated in -0.037 mm + 0.019 mm. The main mineral content and particle size composition of the primary ore flotation tailings are shown in Table 1 and Table 2, respectively.

Table 1 Main mineral content of primary ore flotation tailings (%)

Table 2 primary ore flotation tailings composition and size distribution of metal

The properties of weathered ore flotation tailings are similar to those of primary ore. The WO ₃ content is 0.134%, but the content of black tungsten ore is slightly higher than that of primary ore, accounting for about 25%. The scheelite has a finer particle size, and most of it is concentrated between -0.074mm + 0.019mm. The gangue minerals are mainly composed of feldspar and have many feldspars and iron minerals.

Experimental studies have shown that the use of cyclones, spiral chutes and shakers to enrich tungsten minerals in flotation tailings can reduce the consumption of white tungsten flotation reagents and early recovery of wolframite. That is, the tailings are firstly sorted by a short cone hydrocyclone and then the spiral chute is used to select the coarse concentrate. The coarse concentrate is selected from the wolframite and then floated to the scheelite. See Figure 1 for the WO ₃ content. 47.29%～50.56%, the recovery rate is 18.62%～20.18% concentrate, and the crude concentrate with the yield of 26.95%～34.027% needs to be further floated by white tungsten, compared with single flotation The amount of white tungsten selected is reduced by 73.05% to 65.97%, which can save a lot of dosage and reduce the cost of mineral processing.

Figure 1 Test procedure