INORGANIC INDUSTRIAL WASTE WATER TREATMENT

Inorganic industrial wastewater

Inorganic industrial wastewater is produced mainly in the coal and steel industries, in the non-metallic mineral industry, and in commercial enterprises and metal surface treatment industries. iron smelting and electroplating plants). This wastewater contains a large proportion of suspended matter, which can be removed by sedimentation, often with chemical coagulation through the addition of iron or aluminum salts, coagulants, and certain polymers. Organic.

Purification of warm and dusty exhaust gases from blast furnaces, converters, coke ovens, waste and sludge incinerators, and aluminum structures results in wastewater containing dissolved inorganic and mineral substances. soluble and insoluble.

Pre-cooling and subsequent blast furnace gas cleaning requires up to 20 m3 of water per ton of cast iron. On the way into the gas cooler, the water will absorb fine particles of ore, iron and coke, which is not easy to settle. Gases are dissolved therein, especially carbon dioxide and compounds of alkali and alkaline earth metals, if they are soluble in water or if they are dissolved from the solids by the gases that wash out with them. .

In the process of separating coal from dead rock, the usual transport and separation medium is water, which then contains a large amount of coal and rock particles and is called coal washing water. Coal wash water is recycled after removing coal and rock through flotation and sedimentation.

Other wastewater from rolling mills contains mineral oil and requires additional installation, such as scum boards and oil separators, to capture and remove mineral oil. The emulsified oil residues remaining in the water also require chemical coagulation.

In many cases, wastewater generated in addition to solids and oils, also contains extremely hazardous dissolved substances. These include blast furnace gas washing wastewater containing cyanide, waste from the metal processing industry containing acids or alkaline solutions (mainly non-ferrous and often cyanide or chromate), wastewater from industries from the eloxal process and from the flue gas filtration of aluminum structures, which in both cases contain fluoride. Small and medium-sized non-metallic mineral production plants and metal processing plants are well located for them to discharge wastewater into municipal wastewater systems and must treat or purify the wastewater before discharge according to local regulations.