Method of baking ceramsite by using sludge

Abstract

The invention discloses a method of baking ceramsite by using sludge. The method firstly executes sludge drying to the mechanically dehydrated sludge of sewage treatment plant or sludge dredged by rivers in a special sludge drying device, and respectively reduces the water ratio and volume of the sludge to less than 30% and less than one third. Then a special press presses the sludge into material ball, baking the sludge material ball under 1000 to 100 degrees centigrade, forming sludge ceramsite; the hot fume exhausted when bakes the sludge ceramsite is taken as the thermal resource. Compared with the method taking clay, sub-clay, shale as the raw materials to bake ceramsite, the method in the invention has less energy consumption and lower production cost, and starts a new route of treatment of wastes with processes of wastes against one another and sludge resource treatment of waste cyclic utilization.

Description

technical field [0001] The invention relates to a method for firing ceramsite, in particular to a method for firing ceramsite with sludge. Background technique [0002] Urban domestic sewage and industrial wastewater must be treated by sewage treatment plants, and can only be discharged after reaching the national sewage discharge standard. This is an indispensable environmental engineering measure for urban ecological environment construction. However, during the purification process of various sewage, most of the pollutants in the sewage are transferred to the sludge. According to the National Environmental Protection "Eleventh Five-Year" Plan, by 2010 all cities in my country will build sewage treatment facilities, and the urban sewage treatment rate will not be lower than 70%. It is estimated that the national urban sewage treatment capacity will exceed 100 million tons per day. The accompanying sludge (with a moisture content of about 80%) will be as high as 30 million ...

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Problems solved by technology

[0003] At present, my country mainly adopts temporary landfill disposal method for urban sewage treatment plant sludge and river and lake dredging sludge, which not only costs a lot of money and occupies a lot of land resources, but also causes serious secondary pollution to the ecological environment, especially The sewage in the sludge seeps down, and the harm to groundwater resources is even more unpredictable

Facing the reality that the environmental problems caused by sludge are becoming increasingly acute and the hazards of sludge are increasing, people try to use sludge as fertilizer for agriculture or greening. However, various heavy metals and persistent organic pollutants contained in sludge Limiting the adaptability of soil to sludge utilization, they will be enriched in the soil and enter the food chain through the absorption of crops, eventually endangering human health

[0004] Some places try to achieve the purpose of sludge reduction through incineration, but the investment in sludge incineration equipment is high, the energy consumption is large, and the operation cost is expensive. The cost of sludge incineration is more than 400 yuan / ton, plus sludge During incineration, it will bring pollution to the atmospheric environment and the residue after incineration still needs to be disposed of. According to my country's national conditions, sludge incineration is economically unaffordable.

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