CS240878B1 - The method of reducing gaseous arsenic exhales in the condensation melting of copper concentrators - Google Patents

Abstract

The reduction of gaseous arsenic exhalates during the concentration smelting of copper sulphide concentrates is achieved by using slags with the addition of calcium oxide and a reduced content of silicon dioxide, while the total content of slag-forming additives and the amount of slag remain unchanged.

Description

The invention relates to the concentration melting of sulphide copper concentrates in which the reduction of gaseous arsenic pollutants is solved.

In pyrometallurgical media production, arsenic is partitioned between condensed and gaseous concentration melting and converging products. With waste products, arsenic can get into the environment and endanger the environment. · During concentration smelting, arsenic contained in the plant is divided between stone, waste slag, drift and off-gases. Arsenic is bound in the waste slag in the form of stable, environmentally-friendly chemical compounds · Arsenic in the stone is progressing into a technological conversion operation where it is disposed of. The flux from the concentration melting is repeated. The amount of arsenic that passes into the flue gas at concentration range 50 to 60% of the total amount of arsenic contained in the batch at concentration melting. In the conversion process, due to the high concentration of sulfur dioxide, the off-gases are typically used to produce sulfuric acid, while also escaping arsenic is trapped and destroyed. Thus, the main channel of arsenic leakage into the environment in the process of producing media is the off-gases from the concentration melting process. At concentration melting in non-intensified plants, there is no economically effective method of arsenic capture yet.

The above-mentioned drawbacks are overcome by the method according to the invention, which consists in using slags with a calcium content of 10 to 20% by weight and a silica content of 25 to 35% by weight in concentrating melting. thereby reducing arsenic transfer to off-gases to 13 to 26% of the arsenic contained in the feed.

- 3Example

240 878

A sulfide feedstock having an average content of 31.6 wt% Cu and 1.82 wt% Ae was used for melting. Furthermore, 0.23 kg / kg of sulphide feedstock and 0.20 kg of sulphide feedstock were used. · Melt 9 mixed with 0.86 wt% As and slag containing 0.45 wt% As, 12.72 wt% CaO, 32.85 wt% SiOg. 26% of As from the total arsenic content of the sulphide feedstock went into the bricks.

Example

A sulfide feedstock with an average content of 31.6 wt% Cu and 1.82 wt% As was used for melting. Further, calcium oxide was used in an amount of 0.26 kg / kg sulfide feedstock and silica in an amount of 0.26 kg / kg sulfide feedstock. Melting of the mixed batch yielded a pebble containing 0.98 wt% As and a slag containing 0.58 wt% As, 19.52 wt% CaO, 26.15 wt% SiOg. ^Do dusts passed 13% and the total content of arsenic in sulfidic raw material.

Claims (1)

OBJECT OF THE INVENTION 240878 The process reduces gaseous arsenic exhalations in the final melting of copper concentrates, characterized in that slags with a content of 1G to 20% by weight of oxide calcium and 25 to 35% by weight of silica are used.