Sludge oxidation pellets and manufacturing method

Abstract

The invention discloses a sludge oxidation pellet and a manufacturing method. The sludge oxidation pellets of the present invention are mainly made of the following raw materials in weight percentage: 5-50% of stainless steel cold-rolled heavy metal sludge, 30-70% of iron fine powder, 2-8% of composite binder, carbon powder 4-15%, moisture 10-30%. The above-mentioned method for producing sludge oxidation pellets mainly includes pretreatment of raw materials, mixing of raw materials, pelletizing, and roasting. The purpose of the sludge oxidized pellets is to be used as a blast furnace raw material. The invention solves the problem that the prior art cannot effectively process and comprehensively utilize the stainless steel cold rolling heavy metal sludge.

Description

technical field [0001] The invention belongs to the field of comprehensive utilization of stainless steel cold-rolled heavy metal sludge, and relates to the use of stainless steel cold-rolled heavy metal sludge; the invention also relates to a kind of sludge oxidation pellets, in particular to the production of stainless steel cold-rolled heavy metal sludge as the main raw material The sludge oxidation pellet; the present invention also relates to the manufacture method and application of the sludge oxidation pellet. Background technique [0002] In the pickling process of stainless steel coils, a large amount of pickling wastewater will be produced, and the main pollutant components are: T.Fe, Cr 6+ , T.Cr, Ni 2+ , F - , SO 4 2- , S.S., Zn 2+ , Pb 2+ Wait. At present, the most mature and widely used treatment process for this kind of pickling wastewater is the chemical reduction precipitation method. The chemical reduction precipitation method can be divided into "ch...

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Problems solved by technology

[0007] When stainless steel cold-rolled heavy metal sludge is used as raw material for cold-set pellets, the chemical composition of the sludge fluctuates greatly and the impurity elements S and F in it are not removed in the pretreatment, and the compressive strength of the pellets without roasting is not high, and the softening temperature The range is wide, the reflow dripping performance is not good, and the reduction expansion rate is high at high temperature. When applied to a blast furnace, it will not only cause a decrease in air permeability and a rapid increase in pressure resistance, but also impurity elements in the pellets will enter the molten iron to desulfurize the subsequent molten iron. increase the burden

[0008] When stainless steel cold-rolled heavy metal sludge is mixed as sintering raw material for sintering reuse, due to the large fluctuations in moisture content and chemical composition in the sludge, it is difficult to mix with iron fine powder in a wet mud state during mixing, and the fluorine vapor continuously released during roasting (HF, SiF 4 etc.) will cause serious corrosion to the sintering machine and its ancillary equipment. At the same time, if the amount of sludge added exceeds 5%, it will cause a decline in the yield of sintered ore and the index of the drum, thus affecting the smooth running of the sintering machine.

[0009] So far, there is no economical and effective treatment and comprehensive utilization technology at home and abroad for the stainless steel cold-rolled heavy metal sludge with a large amount and a wide range of hazards and resources. The shortcomings of the existing technology are as follows: (1) Treatment process It involves different processes such as collection, transportation, storage and multiple industries, which not only increases the treatment fee, but also has the hidden danger of pollution transfer; (2) the amount of sludge consumed during the blending treatment is small, and it is not an industry demonstration, and it is harmful to the industry. The metallurgical properties of sludge lack in-depth analysis; (3) The comprehensive utilization process is relatively complicated, the operation is not stable, and there are Cr 3+ Converted again to Cr 6+ (4) The market of by-products is limited, and the environmental safety is worthy of in-depth evaluation; (5) Due to the low grade of valuable resources of sludge and the high cost of comprehensive utilization, most of the resources are not fully utilized, which is harmful environmental risk

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