Method and system of preparing ceramsite from municipal sludge

Abstract

The invention discloses a preparation method of sludge ceramsite, which comprises the steps of pelletizing municipal sludge and clay in a pelletizer to form pellet cores with a particle size less than2mm, conveying the pellet cores into a ball forming mill to form mixed pellets through interaction among the pellet cores, and performing drying, roasting and cooling to form the ceramsite at last. High temperature waste gas after roasting enters a drier; energy of the high temperature waste gas is used for drying the pellets; the waste gas after the drying is sent to a roasting machine from an inlet; harmful gas such as odor in the waste gas is decomposed and burnt in a high temperature environment of the roasting machine; and the emission of the harmful gas is reduced. The ceramsite prepared by the method can meet requirements of structural concrete on strength of aggregate, is used for engineering construction of roads, bridges and the like, and can be also used for virescence, pollution treatment and the like as an adsorbing material. Water is not required to be added; a combination of internal combustion and external combustion of ceramsite roasting is achieved by combustibilityof organic substances in the sludge; the energy is saved; and secondary pollution is avoided.

Description

technical field [0001] The invention belongs to the technical field of sludge treatment, in particular to a method for preparing ceramsite by utilizing urban sludge. Background technique [0002] Worldwide, the disposal methods of municipal sludge mainly include landfill, land use and incineration. Among them, incineration can remove combustible and harmful substances in sludge. It is a relatively thorough and harmless treatment method at present, but the investment in incineration equipment is large. High energy consumption, expensive operation costs, easy to produce secondary pollution. Therefore, it is imperative to seek a harmless and resourceful sludge treatment and disposal process suitable for my country's national conditions. [0003] Dry sludge contains 35%-65% organic matter, and its calorific value can reach 10000kJ / kg, which can be used as fuel. The inorganic substances in dry sludge contain elements such as Si, Ca, Al, etc., which can be used as raw materials ...

AI Technical Summary

Problems solved by technology

[0005] In order to overcome the shortcomings of the above-mentioned existing municipal sludge drying and incineration technology, the purpose of the present invention is to provide a method for preparing ceramsite from municipal sludge, and make raw materials such as sludge into mixed raw pellets, which greatly reduces the drying time. The amount of harmful gases released during the process, the amount of urban sludge mixed can reach more than 40% of the raw materials, increasing the amount of sludge added, can greatly alleviate the pollution of sludge to the city

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