SU1386261A1 - Method of cleaning air from sulphur dioxide - Google Patents

Abstract

The invention relates to the technology of air purification from SOj, used in non-ferrous metallurgy and sulfuric acid production, and allowed to increase the degree of purification and reduce the consumption of lime. Air containing 0.18–0.22 vol.% SO splashes H & s slurry, consisting of limestone and copper smelter production effluent, obtained by thickening, filtering and drying copper concentrate pulp. The ratio of solid to liquid suspension is 1: 9, the initial pH is 7.2-7.6, the final pH is 4. The temperature of the purified air is 20-50 C. The wastewater used may contain the following ingredients, g / l; C 0,020-0,500; Fe 0.0001-0.004; Ca 0.100-0.900 Mg 0.020-0.060; K 0,010 - 0,080J Na 0,200-3,00 Pb 0,005-0,006, Zn 0,009-0,020 {Cl 0,060-0,800; sulfate ions 0,200-1,000; water up to 1 l. With a sparging rate of 60 ppm, the method ensures complete removal of SO from a limestone consumption of 2.9-3.2 g / m of gas. 1 hp f-ly, 1 tab. S

Description

113

The invention relates to the purification of gases from sulfur dioxide and can be used in the copper-smelting and sulfur-acid industries for the purification of low-concentration exhaust gases.

The purpose of the invention is to increase the degree of purification and reduce lime consumption.

Example 1. In a reaction vessel with a diameter of 0.028 m and a height of 0.20 m, 10 g of a cleaning suspension is placed. A suspension is prepared by mixing a known

nka containing 76.25-96.78 wt.% CaCOE, ground to a fraction of 74 microns, with copper-smelter wastewater produced during thickening, filtration and drying of copper concentrate pulp. The solid-to-liquid ratio is 1: 9, the initial pH of the suspension is 7.2-7.6. Through this suspension with a speed of 60 ml / min, air emitted from the sulfuric acid shop is bubbled into the atmosphere containing 0.2% by volume of sulfur dioxide. The temperature of the purified air is 50 ° C. During the purification process, the pH of the suspension and the content of sulfur dioxide in the purified gas are CONTINUED. Air purification is carried out until the suspension has a pH of 4.0, after which the spent suspension is replaced with fresh

Copper smelter wastewater contains active ingredients in the following amount, g / l:

0.020

0,004

0,100

. 0.060

0.080

0,200

ony0,200.

0.060

0,005

0.020

The degree of purification of air from sulfur dioxide is 100%, the specific consumption of lime is 3.2 g / m of purified air, and the productivity of this suspension is 0.031 m of gas per 1 ml of suspension.

Example 2. Air containing 0.18 OBD of sulfur dioxide at 35 ° C is bubbled through a slurry prepared from 1 g of limestone containing 96.78% calcium carbonate and 9 ml of copper smelter waste water.

five

0 0

production containing active ingredients in the following quantity,

Copper

Iron

Calcium

Magnesium

Potassium

Sodium

Sulphate ions

Chlorine

Lead

Zinc

0,500

0.0001

0.800.

0.020. 0,010.

3,000

1,000

0,800

0,006

0,009

The degree of air purification from sulfur dioxide is 100%, the specific consumption of lime is 2.9 g / m of purified air, and the productivity of this suspension is 0.034 m of gas per 1 ml of suspension.

Example 3. Air containing 0.22% by volume of sulfur dioxide is bubbled at 20 ° C through the suspension, pod-. Production of 1 g of limestone containing 5% of 80.2% calcium carbonate, and 9 ml of copper production melt water containing the active ingredients in the following amount, g / l:

. Copper0,340

Iron 0,002

Calcium. 0.560

Magnesium, 0.340.

Potassium0.025

Sodium1,400

Sulfate ions 0,620

Chlorine0,420

Lead, .005

Zinc .0.009

The degree of air purification from sulfur dioxide is 100%, the specific consumption of lime is 3.0 g / m of purified air, and the productivity of the specified suspension is 0.033 m of gas per 1 ml of suspension.

In examples 1-3, the ratio of the active components with the use of waste water from copper-copper production was not specifically chosen. We used those wastewaters that were dumped at a particular point in the production process, i.e. the degree of purification of 100% was obtained regardless of the quantitative ratio of the active components.

The table shows the comparative data on the degree of purification and lime consumption of the proposed and known methods.

Thus, the proposed method allows to achieve complete purification of air from sulfur dioxide (100%) and reduce lime consumption per 1 m of gas to be purified to 2.9-3.2 g / m of gas compared to 5.3 g / m of gas in the known way. In addition, copper smelting waste is used: waste water, with which copper is lost, and sulfuric acid production waste gases, with which sulfur is lost, for their neutralization. At the same time, these wastes are concentrated in the form of sludge from the spent suspension and can be returned to the process of electrofusion of copper and the production of sulfuric acid in order to further extract copper and sulfur.

Claims (2)

1. The method of purifying air from sulfur dioxide by treating with a suspension, which is 25 tons of limestone and aqueous plant a thief containing a catalyst for the oxidation of sulfite bisulfite ions to sulfate ions c. a form of sulphate and ferric chloride, characterized in that, in order to increase the degree of purification and reduce the consumption of lime, the wastewater of a copper smelter is used as an aqueous solution. 2. The method according to claim 1, characterized in that use wastewater with the following content of ingredients, g / l: five 0 five Copper Iron Calcium Magnesium Potassium Sodium Lead Zinc Chlorine Sulphate ions Water 0.020-0.500 0.0001-0.004 0.100-0.900. 0,020-0,060 0,010-0,080 0,200-3,000 0,005-0,006 0,009-0,020 0,060-0,800 0,200-1,000 The rest is up to 1 l Known 0.20 Suspension izvest- ka stn + iron sulfate 5.3