TW201722861A - A method of recycling the sludge generated by the steel works and made it as the auxiliary material for steel works manufacture - Google Patents

Abstract

This invention relates to a method of recycling the sludge generated by the steel works and made it as the auxiliary material for steel works manufacture, which is used the waste sludge generated by the steel rolling etch cleaning process of the steel works, or to mix it with the calcium fluoride sludge generated by the other factory but not the steel works to form a compound sludge. Then a plurality of steel-making recycling fluorite with metal oxide component and calcium fluoride component are manufactured by said sludge dewatering, mixing, pressing block and drying, etc. so that the calcium fluoride component of the steel-making recycling fluorite can be used as the flux for replacing natural fluorite, and the metal oxide component of the steel-making recycling fluorite can be used as the auxiliary material for deoxidizing and melting part of the metal oxide component in the liquid steel and part of the metal oxide component as the reducing agent, to reduce the cost of the steel works. Therefore, the waste sludge generated by the steel works can be recycled as auxiliary materials for the production of steel works, and to achieve the environmental protection effect.

Description

Method for recycling sludge produced by steel mills to produce auxiliary materials for steel plants

The invention relates to a method for recycling sludge generated by a steel plant to produce auxiliary materials for a steel plant; in particular, a waste sludge generated in a pickling process of a steel mill through a rotary kiln, stirring, briquetting, And drying and other procedures to produce a steel-recycled fluorite having a metal oxide and a calcium fluoride component, and then using the calcium fluoride component contained in the steel-regenerated fluorite as a flux in the steelmaking process, The metal oxide component contained in the steel-recycled fluorite is reduced and melted in the molten steel to be used as an auxiliary raw material for production, so that the waste sludge produced by the steel mill can be recycled and used as a auxiliary raw material for the steel plant.

According to the general steel mill in the steel rolling production process, the waste water generated in the pickling and etching process, after chemical coagulation, precipitation and dehydration treatment by adding calcium salt, will produce a large amount of metal oxide components (content of about 15% to 60%). ) Inorganic sludge with calcium fluoride (content of about 15% to 45%), and the cost of these sludges to directly reduce the metal oxides inside is very high and does not meet economic benefits; The mill will supply the sludge to the cement plant for use in the cement. However, the amount of sludge that can be added to the cement is much smaller than the amount of sludge produced by the mill, so the mill also needs to face the remaining Sludge problem.

Therefore, all steel mills have to use this sludge as waste, and they have to spend money to entrust the environmental cleaning company to carry the sludge to the landfill. This will increase the cost of the steel mill and cause environmental problems.

To this end, the inventors of the present invention invented the case in view of the research and practice experiments on the waste sludge generated by the former Zhizhi Steel Plant and the environmental recycling and reuse of many years of resources.

The object of the present invention is to produce a steel-recycled fluorite by using a large amount of a metal oxide component and a calcium fluoride component contained in waste sludge generated by a steel plant to regenerate the steelmaking. Fluorite can replace natural fluorite in the steelmaking process of the steel mill and provide auxiliary materials for production to reduce the use and cost of raw materials for the steelmaking process, achieve the environmental protection effect of waste recycling and reuse, and create a green earth.

The method for recycling sludge generated by a steel plant to a steel plant for producing auxiliary materials comprises the first step of drying the sludge produced by the steel plant; the second step is drying after the treatment The sludge is subjected to a stirring process; in the third step, the agitated sludge is subjected to a briquetting process to obtain a plurality of sludge blocks; and in the fourth step, the sludge block is subjected to a drying process to obtain a plurality of sludges. Steel regeneration fluorite; the fifth step is to calculate the ratio of various metal oxides and calcium fluoride contained in the steel-regenerated fluorite, and the steel-recycled fluorite can be used in the steelmaking process. The calcium fluoride component of the stone is used as a flux to increase the fluidity of the slag, and the metal oxide contained in the steel can be partially reduced and melted in the molten steel while the steel-regenerated fluorite is used as a flux. It is used as a reducing agent, so that the sludge discharged from the steel mill can be fully recovered and used as an auxiliary material for steel mill steel production, and at the same time, it can reduce the cost and prevent environmental pollution.

The invention recovers the sludge produced by the steel plant into a method for the steel plant to produce auxiliary raw materials, wherein the sludge produced by the steel mill is mixed with the calcium fluoride sludge produced by the other non-steel plants to form a blending pollution. mud.

The method for recycling sludge generated by a steel plant to a steel plant for producing auxiliary materials, wherein the foregoing second step and the third step can be repeated, and the air in the sludge is obtained through multiple stirring and briquetting It is fully extruded to obtain a plurality of solid sludge blocks.

The method for recycling sludge generated by a steel plant to a steel plant for producing an auxiliary raw material, wherein the sludge moisture content of the first step is 15% to 25%, and 20% is optimal.

The method for recycling sludge generated by a steel plant to a steel plant for producing auxiliary materials, wherein a binder is added in the stirring procedure of the second step to increase the structural strength of the steel-regenerated fluorite.

In order to further understand the present invention, the preferred embodiment of the method for recycling sludge produced by a steel plant into a steel plant for producing auxiliary materials (I) is as shown in FIG. 1 and includes at least:

In the first step 11, the sludge produced by the steel plant is subjected to a drying process to remove excess water in the sludge, and the moisture content of the sludge is controlled within a range of 15% to 25%, and 20% is the most Good, but can not be completely dry, otherwise the sludge will not be pressed into a block; the above drying process can be a rotary kiln drying technology, or other suitable drying means. Furthermore, since the sludge produced by the electronics factory, the metal pickling plant or the metal etching plant has a higher proportion of calcium fluoride, the sludge produced by the steel plant of the first step 11 is premixed. Calcium fluoride sludge produced by non-steel plants to form a blended sludge, and through the blending of two kinds of sludge, allows the manufacturer to adjust the blended sludge of the desired ratio of metal oxide to calcium fluoride.

In the second step 21, the dried sludge is subjected to a stirring process to uniformly distribute the sludge. When the above-mentioned blended sludge is used, if the proportion of the component of the blended sludge measured after the drying process of the first step 11 is incorrect, the drying process after the second step 21 is added to the drying process. Steel mill sludge or calcium fluoride sludge to obtain the correct blending sludge ratio.

In a third step 31, the agitated sludge is subjected to a briquetting process to obtain a plurality of sludge blocks (for example, round, round, tapered, polygonal or irregular, depending on the use or manufacturing requirements). In the pressing process, the sludge block is controlled by pressure, and the moisture contained in the interior and other polymers with higher viscosity are squeezed onto the surface of the sludge block to cover the surface of the sludge block. A layer of polymer with viscosity.

In the fourth step 41, the sludge block is subjected to a drying process to solidify the polymer on the surface of the sludge block to obtain a plurality of steel-recycled fluorite. Although the structural strength of the steel-recycled fluorite which is formed by one press is low, if the steel-recycled fluorite is manufactured directly after being transported through a conveyor belt in a steel mill, the steel-recycled fluorite is transported. In the process, since it will not be crushed or crushed, it is not necessary to particularly strengthen the structural strength of the steel-regenerated fluorite; on the contrary, if the steel-recycled fluorite needs to be transported to other places after the completion of manufacture, Adding a binder to the stirring process of the second step 21 to enhance the structural strength of the steel-regenerated fluorite, and avoiding the crushing or impact of the steel-regenerated fluorite during the transportation; the aforementioned binder is obtained. It is made up of a single material or a plurality of materials such as water glass, lithium chloride, sodium chloride, resin, molasses, starch, cement, flour, volcanic mud, etc., depending on the needs of use.

In the fifth step 51, the ratio of various metal oxides to calcium fluoride contained in the steel-regenerated fluorite is calculated, and the steel-recycled fluorite can be applied to the steelmaking process (for example, the steel-regenerated fluorite is put into the refining process). In the process of electric furnace, converter or refining furnace of steel process, the calcium fluoride component of the steel-regenerated fluorite can replace natural fluorite and be used as a flux to increase the fluidity of the slag, and regenerate the steel in the steel slag. As a flux, the stone can be used according to the ratio of various metal oxides (such as iron, chromium, nickel, manganese, titanium, molybdenum and other metal oxides) contained in steel-recycled fluorite. The metal is required to reduce and melt the specific metal oxide in the molten steel, and other metal oxides having a low oxidation number can be used as a reducing agent to reduce the use and cost of the raw material of the steelmaking process, so that the steel mill can be used. The discharged sludge can be fully recovered and used as an auxiliary material for steel mill steel production, and at the same time, it can reduce the cost and prevent environmental pollution.

As shown in FIG. 2, it is an embodiment (2) of the method for recycling sludge generated by a steel plant to produce an auxiliary raw material for a steel plant, and includes at least:

In the first step 12, the sludge produced by the steel plant is subjected to a drying process to remove excess water in the sludge, and the moisture content of the sludge is controlled within a range of 15% to 25%, and 20% is the most Good, but can not be completely dry, otherwise the sludge will not be pressed into a block; the above drying process can be a rotary kiln drying technology, or other suitable drying means. Furthermore, since the sludge produced by the electronics factory, the metal pickling plant or the metal etching plant has a higher proportion of calcium fluoride, the sludge produced by the steel plant of the first step 12 is premixed. Calcium fluoride sludge produced by non-steel mills to form a blended sludge, and through the blending of two kinds of sludge, allows the manufacturer to adjust the blended sludge of the desired ratio of metal oxide to calcium fluoride.

In the second step 22, the dried sludge is subjected to a stirring process to uniformly distribute the sludge. When the above-mentioned blended sludge is used, if the proportion of the composition of the blended sludge measured after the drying process of the first step 12 is incorrect, the drying process after the second step 22 is added to the drying process. Steel mill sludge or calcium fluoride sludge to obtain the correct blending sludge ratio.

In the third step 32, the agitated sludge is subjected to a briquetting process to increase the density of the sludge.

In the fourth step 42, repeating the foregoing second step 22 and the third step 32, through multiple stirring and briquetting (for example, secondary agitation secondary briquetting, tertiary agitation three briquetting, four stirring four briquetting, etc. ), the air in the sludge must be fully extruded to obtain a plurality of solid sludge blocks (such as round, round, tapered, polygonal or irregular shapes, depending on the use or manufacturing needs) In the pressing process, the sludge block is controlled by pressure, and the moisture contained in the interior and other polymers with higher viscosity are squeezed onto the surface of the sludge block to cover the surface of the sludge block. A layer of polymer with viscosity. When the above-mentioned blended sludge is used, it is also necessary to repeat the above-mentioned second step 22 stirring process to add the dried steel sludge or calcium fluoride sludge to obtain the correct blending sludge ratio.

In the fifth step 52, the final pressed sludge block is subjected to a drying process to solidify the polymer on the surface of the sludge block to obtain a plurality of high-strength steel-recycled fluorite. The steel-recycled fluorite which has been repeatedly pressed has high structural strength and is not easily crushed or crushed during transportation; of course, if the structural strength of the steel-regenerated fluorite is to be further increased, The binder in the second step 22 is added with a binder, and the binder is obtained by water glass, lithium chloride, sodium chloride, resin, molasses, starch, cement, flour, volcanic mud, and the like. The material or a plurality of materials are blended, depending on the needs of use.

In the sixth step 62, the ratio of various metal oxides to calcium fluoride contained in the steel-regenerated fluorite is calculated, and the steel-recycled fluorite can be applied to the steelmaking process (for example, the steel-regenerated fluorite is put into the refining process). In the process of electric furnace, converter or refining furnace of steel process, the calcium fluoride component of the steel-regenerated fluorite can replace natural fluorite and be used as a flux to increase the fluidity of the slag, and regenerate the steel in the steel slag. As a flux, the stone can be used according to the ratio of various metal oxides (such as iron, chromium, nickel, manganese, titanium, molybdenum and other metal oxides) contained in steel-recycled fluorite. The metal is required to reduce and melt the specific metal oxide in the molten steel, and other metal oxides having a low oxidation number can be used as a reducing agent to reduce the use and cost of the raw material of the steelmaking process, so that the steel mill can be used. The discharged sludge can be fully recovered and used as an auxiliary material for steel mill steel production, and at the same time, it can reduce the cost and prevent environmental pollution.

Therefore, the inventor of the present invention upholds the spirit of environmentally-friendly recycling and recycling, and uses the sludge containing a large amount of metal oxide and calcium fluoride produced by the steel mill to recycle the waste sludge through the various embodiments described above. The use of auxiliary raw materials in steel mills can not only reduce the cost of steel mills, but also achieve the effect of environmental protection and create a green earth.

The above-described embodiments or the drawings are not intended to limit the scope of the invention, and any suitable variations or modifications may be made without departing from the scope of the invention.

11‧‧‧First steps
21‧‧‧ second step
31‧‧‧ third step
41‧‧‧ fourth step
51‧‧‧ fifth step
12‧‧‧First steps
22‧‧‧ second step
32‧‧‧ third step
42‧‧‧ fourth step
52‧‧‧ fifth step
62‧‧‧ sixth step

1 is a flow chart of an embodiment (1) of the present invention. 2 is a flow chart of Embodiment (2) of the present invention.

11‧‧‧First steps

21‧‧‧ second step

31‧‧‧ third step

41‧‧‧ fourth step

51‧‧‧ fifth step

Claims (10)

A method for recycling sludge produced by a steel plant into a steel plant for producing auxiliary raw materials, comprising at least: the first step: drying the sludge produced by the steel plant to remove excess water in the sludge; In the second step, the dried sludge is subjected to a stirring process to uniformly distribute the sludge; in the third step, the stirred sludge is subjected to a briquetting process to obtain a plurality of sludge blocks; The sludge block is subjected to a drying process to obtain a plurality of steel-recycled fluorite; the fifth step is to calculate the ratio of various metal oxides to calcium fluoride contained in the steel-regenerated fluorite, and the steel can be obtained. The recycled fluorite is used in a steelmaking process, and the calcium fluoride component of the steel-regenerated fluorite is used as a flux to increase the fluidity of the slag, and the steel-regenerated fluorite is used as a flux while being used as a flux. The metal oxide contained may be partially reduced and melted in the molten steel and partially used as a reducing agent, so that the sludge discharged from the steel mill can be Min recycling steel mill as a raw material for the production of an auxiliary, and can simultaneously achieve lower costs and the effect of preventing environmental pollution. According to the scope of the patent application, the sludge produced by the steel plant is recycled into a method for producing auxiliary materials in the steel plant, wherein the sludge produced by the steel plant in the first step is premixed with fluorine produced by other non-steel plants. Calcium sludge is formed to form a blended sludge. According to the second paragraph of the patent application scope, the sludge generated by the steel plant is recycled into a method for producing auxiliary materials in the steel plant, wherein the steel plant sludge or calcium fluoride sludge is added in the stirring procedure of the second step to adjust Blending the proportion of sludge. According to the claim 1 or 2 of the patent application, the sludge produced by the steel plant is recycled into a method for producing auxiliary materials in the steel plant, wherein the sludge moisture content of the drying process of the first step is 15% to 25%. The method for recovering sludge generated by a steel plant according to claim 1 or 2 of the patent application is a method for producing an auxiliary raw material for a steel plant, wherein a binder is added in the stirring procedure of the second step. A method for recycling sludge produced by a steel plant into a steel plant for producing auxiliary raw materials, comprising at least: the first step: drying the sludge produced by the steel plant to remove excess water in the sludge; In the second step, the dried sludge is subjected to a stirring process to uniformly distribute the sludge. In the third step, the stirred sludge is subjected to a briquetting process to increase the density of the sludge; Repeating the foregoing second step and third step, through multiple stirring and briquetting, the air in the sludge is sufficiently extruded to obtain a plurality of solid sludge blocks; the fifth step is to finally press The sludge block is subjected to a drying process to obtain a plurality of high-strength steel-recycled fluorite; the sixth step is to calculate the ratio of various metal oxides to calcium fluoride contained in the steel-regenerated fluorite, ie, The steel-recycled fluorite can be used in a steelmaking process, and the calcium fluoride component of the steel-regenerated fluorite is used as a flux to increase the slag Mobility, and when the steel-recycled fluorite is used as a flux, the metal oxide contained therein can be partially reduced and melted in the molten steel, and partially used as a reducing agent, so that the steel plant can discharge it. The sludge can be fully recovered and used as an auxiliary material for steel mill steel production, and at the same time, it can reduce the cost and prevent environmental pollution. According to the sixth paragraph of the patent application scope, the sludge produced by the steel plant is recycled into a method for producing auxiliary raw materials for the steel plant, wherein the sludge produced by the steel plant of the first step is premixed with fluorine produced by other non-steel plants. Calcium sludge is formed to form a blended sludge. According to the seventh paragraph of the patent application, the sludge produced by the steel plant is recycled into a method for producing auxiliary materials in the steel plant, wherein the steel plant sludge or calcium fluoride is added in the stirring process of the second step or the fourth step. Mud to adjust the proportion of blended sludge. According to the sixth or seventh aspect of the patent application, the sludge produced by the steel plant is recycled into a method for producing auxiliary materials in the steel plant, wherein the sludge moisture content of the drying process of the first step is 15% to 25%. According to the sixth or seventh aspect of the patent application, the sludge generated by the steel plant is recycled into a method for producing auxiliary materials in the steel plant, wherein the binder is added in the stirring process of the second step or the fourth step.