SU632743A1 - Method of leaching sulfide ores - Google Patents

Description

one

The invention relates to non-ferrous metal hydrosallurgy and can be used for complex processing of poor and off-balance sulphide ores under the smelt, heap and percolation of silicon ore {iron 4.

With the technology of the pit gold, heap and percolation leaching, the main task is the complex processing of ore in order to maximize the extraction of all the components.

The known method of leaching sulfide ores with sodium hypochlorite solution (1. According to this method, the processing of sulfide and mixed concentrates and intermediates containing lead, zinc, copper and iron is carried out with an aqueous solution containing 80-100 g / l alkali and 1040 g / l chlorine At the same time, lead and ccnc are transferred into solution, respectively, in the form of plumbate and zincate; the rest of the metals are not leached. The method has the following disadvantages: selective leaching of sulphide ores with respect to lead and zinc, whereas the valuable accompanying elements you (copper, cadmium, silver

gold, ividium, germanium, cobalt, thallium) remain in the ore;

low process rate, which is caused by low oxidative potential of alkali sodium hypochlorite, equal to +0.896 V,

The proposed method is characterized in that hydrochloric acid of 0.1-0.5 g / l and sodium chloride 150-300 g / l are introduced into the initial solution and the active chlorine content is maintained at 0.1-3 g / l. This allows increasing the speed of the process and complex processing of poor sulphide polymetal. .pic ores in underground, heap and percolation leaching.

Sodium hypochlorite in an acidic environment is characterized by a high oxidative capacity and its potential is + 1.63 V, which dramatically increases the dissolution rate of sulfides and reduces the time it takes for leaching dumps.

The hypochlorite chlorine concentration is selected in the range of 0.1-3 g / l, because when leaching poor ore containing 0.2-2% lead, the use of a reagent containing active chlorine is less than 0.1 g / l, inefficient due to low metal recovery .lov in solution. At the same time, the contents. valuable components are not a steppe (it is useful to use active x-pore hypochlorite at the end of its concentration above 3 g / l. Pipienne of the content of active chlorine leads to the transition of impurities into the solution of metals, t., such as iron, aluminum, magnesium , calcium, and organic substances, which further complicates the processing of solutions.

The use of hydrochloric acid leads to a sharp increase in the oxidative potential of hypochlorite and prevents the hydrolysis of metals converted into solution in the form of chlorides. If the acidity is maintained above 0.5 g / l of hydrochloric acid, impurity metals will pass into the solution,

such as calcium, magnesium, iron, aluminum, which complicate the processing of solutions in order to extract valuable metals. Concentration below 0.1 g / l of hydrochloric acid is insufficient to maintain conditions that prevent

hydrate formation.

The use of sodium chloride allows to improve the dissolution of lead, zinc, cadmium, silver due to the formation of low dissociated

complexes, and their best solubility lies within 150300 g / l. On the other hand, sodium chloride stabilizes hypochlorite.

The study was carried out on a sample of lead-zinc oxide ore, the chemical composition of which is given in Table 1.

Table 1

Ae.

SiO,

To simulate the process of underground, heap and percolation leaching, a cylindrical percolator made of organic glass with dimensions: diameter 500 mm, height 1300 mm; weight of ore 100 kg volume of irrigating solution 2 l room temperature, close to the table it is clear that the use of a solution containing the minimum amount of reagents (0.1 g / l of chlorine; 0.1 g / l of HCl;: 50 g / l of nltr chloride; ; davt low ore 50 mm; the number of irrigation plants 2 times a day. For 150 days 75% of lead and 60% of zinc were extracted.

Examples of the method / where the concentrations of metals in the solution after leaching are given are given in Table 2.

table 2

0,0090,006

0,0100,008

0.06 Traces

0,0100,008

0.06 Traces

0,0110,007

0.06 Traces

0,0090,002

0,100,15

0,0120,009

treatment of the main valuable components, and the use of a solution containing the maximum amount of reagents (3 g / l of chlorine; 0.5 g / l of hydrochloric acid; 300 g / l of sodium chloride)

increases the extraction of impurities into the solution of metals, which complicate the further processing of solutions for the extraction of valuable metals. At the same time, the extraction of valuable metals does not increase significantly.

An approximate economic calculation of complex processing of off-balance sulphide ore in the amount of 250000 tons gives an effect of 30,000 p. per year with the condition of daily irrigation of 2500 tons of ore with a solution of sodium hypochlorite in the amount of 125 m

Thus, the use of sodium hypochlorite, containing hydrochloric acid, sodium chloride, and active chlorine within the specified limits, makes it possible to profitably extract all valuable metals at a rather high rate from subsurface sulfide ores.

Claims (1)

1. USSR author's certificate No. 203906, cl. From 22 to 13/04, 1964.