Method for synergistically treating heavy metal sludge in cement production

Abstract

The present invention discloses a method for synergistically treating heavy metal sludge in cement production. The method comprises: (1) carrying out a drying pretreatment on heavy metal sludge so as to make the moisture content be less than or equal to 40 wt%; (2) mixing the obtained heavy metal sludge and a cement raw material to prepare a raw material for cement; and (3) after the raw material for cement is homogenize, firing into a cement clinker. According to the present invention, with the method, the harmless treatment of the sludge and the production of the cement clinker and the product thereof can be simultaneously achieves, such that the heavy metal sludge with characteristics of complex components and difficult recycling is completely digested, and the quality performance of the cement product is not affected.

Description

technical field

[0001] The invention relates to a method for treating sludge, in particular to a method for treating sludge containing heavy metals. Background technique

[0002] Heavy metal wastewater has a wide range of sources and types, and its treatment processes can be mainly classified into chemical, physical, physicochemical and biochemical methods. The chemical neutralization precipitation method using lime milk as the main agent has been widely used at home and abroad because of its mature process route, low cost of wastewater treatment, convenient maintenance and management, and high degree of automation. Sludge has always been the focus and difficulty of corporate environmental governance.

[0003] Taking stainless steel cold-rolled pickling wastewater as an example, the water content of the cold-rolled mud cake after two-stage chemical reduction, lime neutralization, sludge concentration, and plate and frame pressure filtration is 50-70%, and Fe, Cr, Ni, Zn, et...

Examples

Embodiment 1-6

[0039] The method of co-processing heavy metal sludge in cement production was applied to three different heavy metal sludge treatments, and the steps included:

[0040] (1) Naturally dry or use drying equipment to dry and pretreat the heavy metal sludge (with a water content of 50-70wt%) from three different production enterprises to reduce the water content to below 40wt%;

[0041] (2) Add the dry pretreated heavy metal sludge to the cement raw material, and the addition ratio accounts for 1-10wt% of the cement raw material. The heavy metal sludge and the cement raw material are fully mixed in the vertical mill, and the mixture is finely ground After that, it is made into cement raw meal;

[0042] (3) After the cement raw meal is homogenized, it is sent to the calcination system to be fired into cement clinker, and the waste heat and waste gas generated after calcination are passed into the vertical mill in step (2) to dry the cement raw meal.

[0043] It should be noted th...

technical field

[0001] The invention relates to a method for treating sludge, in particular to a method for treating sludge containing heavy metals. Background technique

[0002] Heavy metal wastewater has a wide range of sources and types, and its treatment processes can be mainly classified into chemical, physical, physicochemical and biochemical methods. The chemical neutralization precipitation method using lime milk as the main agent has been widely used at home and abroad because of its mature process route, low cost of wastewater treatment, convenient maintenance and management, and high degree of automation. Sludge has always been the focus and difficulty of corporate environmental governance.

[0003] Taking stainless steel cold-rolled pickling wastewater as an example, the water content of the cold-rolled mud cake after two-stage chemical reduction, lime neutralization, sludge concentration, and plate and frame pressure filtration is 50-70%, and Fe, Cr, Ni, Zn, et...

Examples

Embodiment 1-6

[0039] The method of co-processing heavy metal sludge in cement production was applied to three different heavy metal sludge treatments, and the steps included:

[0040] (1) Naturally dry or use drying equipment to dry and pretreat the heavy metal sludge (with a water content of 50-70wt%) from three different production enterprises to reduce the water content to below 40wt%;

[0041] (2) Add the dry pretreated heavy metal sludge to the cement raw material, and the addition ratio accounts for 1-10wt% of the cement raw material. The heavy metal sludge and the cement raw material are fully mixed in the vertical mill, and the mixture is finely ground After that, it is made into cement raw meal;

[0042] (3) After the cement raw meal is homogenized, it is sent to the calcination system to be fired into cement clinker, and the waste heat and waste gas generated after calcination are passed into the vertical mill in step (2) to dry the cement raw meal.

[0043] It should be noted th...

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