RU2496892C1 - Method for silver flotation from acid cakes of zinc production - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: method for silver flotation from acid cakes of zinc production involves introduction of a collecting agent - butyl xantate and a foaming agent - flotation oil to a flotation pulp of cakes. Prior to introduction of butyl xantate and flotation oil, pulp is subject to conditioning with tetrachloroethylene supplied in the form of water emulsion that has passed ultrasonic treatment.

EFFECT: increasing silver content in concentrate, which is achieved owing to removing elemental sulphur from mineral surface.

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Description

The invention relates to mineral processing and can be used in the processing of acid cakes of zinc production.

Zinc concentrates coming from concentrating plants to metallurgical processing, after expansion, are subjected to oxidative roasting, and then leached in sulfuric acid. As a result of leaching, the main amount of zinc passes into a solution, which, after purification, is sent to electrolysis. After leaching cake containing silver 200-400 g / t is processed using the Waelz process; while silver goes into clinker, which is smelted at smelters together with copper concentrates [1]. The disadvantage of this method is the large (up to 12%) loss of silver.

Reducing the loss of silver can be achieved by flotation of acid cake zinc production [2].

A known method of flotation of silver from acid cakes of zinc production, in which flotation is carried out using xanthogenate as a collector reagent (flow rate 250-300 g / t), and T-80 flotation oil as a blowing agent reagent, flow rate 40-60 g / t, flotation duration 10-15 minutes [3]. Testing this method on different samples of cakes showed that the level of extraction of silver in the concentrate ranges from 30 to 70%, and the silver content in the concentrate after two-fold cleaning is from 2 kg / t to 6.0 kg / t [2]. Such a wide variation in extraction indicates that the level of silver extraction achieved depends primarily on the mineralogical composition (ratio of glucophan and marmatite, copper and iron content), zinc concentrates subjected to oxidative roasting before zinc is leached with sulfuric acid, and also on conditions leaching. An obvious disadvantage of this method is the low silver content in the resulting flotation concentrates complicating their further processing. The low quality is due to the fact that during the leaching of zinc concentrates on the surface of silver-free minerals, elemental sulfur is formed which, by hydrophobizing the surface of the minerals, leads to their transition into a foam product, as a result of which the concentrate yield increases and the silver content in silver-containing

concentrate is reduced.

The technical result that can be obtained by using the described method — increasing the silver content in the concentrate — is achieved by removing elemental sulfur from the surface of minerals that are not silver carriers, by introducing emulsified tetrachlorethylene into the technological process, which dissolves sulfur and thereby reduces the flotation activity of these minerals.

Tetrachlorethylene is a colorless liquid, density 1.6 g / cm3, solubility in water 150 mg / dm ³ , non-combustible, not self-igniting, non-explosive. Previously, chlorethylenes (trichlorethylene, perchlorethylene) were used in the flotation of talc as a collector reagent. [four]

The inventive method of flotation of silver from acid cakes of zinc production, comprising introducing into the pulp a collector - butyl xanthate and a blowing agent - flotation oil, characterized in that before the introduction of xanthate and blowing agent, the pulp is subjected to conditioning with tetrachlorethylene, which is supplied in the form of an aqueous emulsion that has undergone ultrasonic treatment.

Ultrasonic treatment promotes the emulsification of tetrachlorethylene, which leads to an increase in its effectiveness and a decrease in consumption.

After the main flotation, the coarse silver-containing concentrate is subjected to double purification. A feature of the proposed method is the fact that the action of tetrachlorethylene does not stop during the cleaning operations, contributing to an increase in the silver content in the concentrate.

Tetrachlorethylene dissolves elemental sulfur, which forms on the surface of minerals during the leaching of zinc from zinc concentrates, preventing the transfer of minerals not containing silver to concentrate. All this increases the efficiency of separation of silver-containing minerals and leads to an increase in the silver content in the concentrate. In this case, the yield of the concentrate decreases, and the extraction of silver in the flotation concentrate remains at the achieved level.

Example

The proposed method floated acid cake of zinc production containing zinc 14.54%, silver 320 g / t, sulfur 7.1%. The reagent and technological flotation conditions corresponded to those recommended in [3], but tetrachlorethylene in the form of an aqueous emulsion that underwent ultrasonic treatment was additionally introduced into the pulp conditioning operation before flotation. The results of the experiments are presented in tables 1 and 2.

An analysis of the data shows that pre-conditioning the pulp with tetrachlorethylene before flotation of silver-containing minerals leads to a decrease in the yield of the concentrate due to a decrease in the content of minerals in which there is no silver and an increase in the silver content in the concentrate.

Literature

1. Romanteev Yu.P., Fast V.P. Metallurgy of heavy non-ferrous metals. Lead. Zinc. Cadmium: - M.: MISiS Publishing House, 2010. - 575 p.

2. Chinkin VB Processing of flotation concentrates of zinc cake with the extraction of silver // Non-ferrous metals No. 12. S.18-20. 2001.

3. Geykhman VV The effectiveness of flotation in the processing of zinc cakes // Non-ferrous metals, 2000. No. 5. S.32-34.

4. Shubov L.Ya. Flotation reagents in the processes of mineral processing // M .: Nedra, 1990, 400 p.

Claims (1)

A method of flotation of silver from acid cake of zinc production, including introducing into the flotation pulp from cake of a collector - butyl xanthogenate and blowing agent - flotation oil, characterized in that before the introduction of butyl xanthogenate and blowing agent, the pulp is subjected to conditioning with tetrachlorethylene, which is supplied in the form of an aqueous emulsion, which has been processed .