KR100376155B1 - Manufacturing method making cement from dust and sludge - Google Patents

Abstract

The present invention relates to a method for producing cement using sludge of dust and waste water of steelmaking, and more specifically, it is possible to omit a separate heating process by heating in a kiln, and to remove heavy metals and halogen salts by using CaCO ₃ of limestone. The purpose of the present invention is to provide a method for producing cement using sludge of dust and wastewater of steel, which can prevent environmental pollution by neutralizing.

In order to achieve the above object, the present invention mixes and grinds limestone, clay raw material, iron oxide raw material, etc., and then, after preheating of the preheater and firing of the kiln, produce the clinker state, and then grind together with gypsum in the grinder. A method for producing cement, comprising the steps of: combining 2% by weight of inorganic sludge of wastewater mixed with limestone powder and 2% by weight of dust of steelmaking steel with 96% by weight of raw materials such as limestone; Preheating to 800-900 ° C. in a preheater; It provides a method for producing cement using the sludge of the dust and waste water of the steelmaking steel, comprising the step of firing at 1450 ~ 1500 ℃ in the kiln.

Description

MANUFACTURING METHOD MAKING CEMENT FROM DUST AND SLUDGE}

The present invention relates to a method for producing cement using sludge of dust and wastewater of steelmaking, and more particularly, to inorganic sludge generated during wastewater treatment instead of clay raw materials and iron oxide raw materials, which are conventional raw materials used in the manufacture of cement. The present invention relates to a method of manufacturing cement using sludge of dust and wastewater of steel, which is manufactured by recycling dust generated during steelmaking and steelmaking.

Currently, domestic waste and steel waste dust is estimated at 50,000 tons per year, and inorganic waste sludge is estimated to generate about 100,000 tons. Waste dust and inorganic waste sludge at landfill costs of KRW 7.5 billion per year. On the other hand, according to the cement manufacturing method using a conventional waste sludge, the process for drying and grinding the inorganic waste sludge at 100 ~ 110 ℃, and the material, portland cement, frying ash after drying at 500 ~ 1000 ℃ This is a method for producing high strength cement by mixing silica, additives, and additives. However, this method of manufacturing cement using waste sludge has problems such as complicated heating process and causing secondary problems such as environmental pollution.

The present invention has been made in order to improve such a conventional problem, it is possible to omit a separate heating process by heating in a kiln, and to prevent environmental pollution by neutralizing heavy metals and halogen salts using CaCO ₃ of limestone. An object of the present invention is to provide a method for producing cement using sludge of dust and wastewater of steelmaking.

1 is a manufacturing process diagram illustrating the prior art,

2 is a manufacturing process diagram illustrating an embodiment of the present invention.

In order to achieve the above object, the present invention mixes and grinds limestone, clay raw material, iron oxide raw material, etc., and then, preheats the preheater and calcinates the firing furnace to produce clinker, and then grinds together with gypsum in the grinder to produce cement. A method for producing cement, comprising the steps of: mixing 2% by weight of inorganic sludge in wastewater mixed with limestone powder and 2% by weight of dust in steelmaking together with 96% by weight of raw materials such as limestone; Preheating to 800-900 ° C. in a preheater; It is to provide a method for producing cement using the sludge of the dust and waste water of the steelmaking steel, comprising the step of firing at 1450 ~ 1500 ℃ in the kiln.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a manufacturing process diagram illustrating an embodiment of the present invention.

In general, the main component of the cement is a compound such as SiO ₂ , Al ₂ O ₃ , Fe ₂ O ₃ , CaO, etc., and the quality and characteristics of the cement must be constant, and the raw material is mixed with limestone, pumice, lead, iron oxide, etc. The content of the main component is mixed to meet the following Table 1.

TABLE 1

At this time, the mixed raw materials are put into a firing furnace at 1450 ° C. to 1500 ° C. to produce a clinker, and after mixing gypsum, which is a coagulant retardant, with the clinker, the finished product is made. 88 to 90% by weight of limestone, clay material is about 8 to 10% by weight, iron oxide material is about 2% by weight. According to an embodiment of the present invention, limestone, clay material used in the production of cement In the iron oxide raw material, clay raw material is used as wastewater sludge in wastewater treatment plant, and iron oxide raw material is used as a substitute for steelmaking. First, after collecting the steel dust dust scattered in the steelmaking process of blast furnace or electric furnace, In the ferretized state, it is transported and stored in a raw material collection station of a cement manufacturing facility to be used as a substitute for the existing iron oxide raw material during cement production. Inorganic crystal sludge of wastewater generated in the treatment plant is transported and mixed with limestone powder, dried at 200 ℃ in a simple drying furnace to lower the moisture content, and transported and stored in a raw material collection station in this state as a substitute for the existing clay material during cement production. At this time, in the present invention, the raw material mixing ratio of cement is determined according to the chemical analysis table of each raw material component as shown in Table 2 below. The dust of the steel and the sludge of the waste water thus made is mixed with the limestone at a raw material mixing ratio determined according to the chemical analysis table of Table 1 above, the raw material mixing ratio of the cement according to the present invention is 90% by weight limestone, 2 weight of steel steel dust %, 8% by weight clay material, 90% by weight limestone, 2% by weight wastewater sludge, 6% by weight clay material, 2% by weight iron oxide, or 90% by weight limestone, 2% by weight wastewater sludge, pumice stone % By weight and 2% by weight of steelmaking dust. Here, the components of sludge of dust and wastewater of the steelmaking steel used in the present invention are analyzed as shown in Table 3 below. Steel Steel dust used in the present invention as a suitable alternative to traditional iron oxide raw material in the production of cement content of the iron of up to 55.9% by weight as shown in Table 2, the Cr ^+6, as shown in Table 3 4.776ppm However, since it is mixed within 2% of the total raw materials, the Cr ⁺⁶ content is lowered to 0.095 ppm, which is below the standard value of 1.5 ppm, and it is safe. Furthermore, the dust of steel is CaCO ₃ during the preheating process of 800 ~ 900 ℃. And the harmful metals are removed by neutralizing the heavy metals and halogen salts as shown in Table 3. After pulverizing the mixed raw materials below 100㎛ according to the raw material mixing ratio The preheating process is followed by the following chemical reactions to produce exhaust gases: CaCO ₃ → CaO + CO ₃ CaO + 2HCl → CaCl ₂ + H ₂ OCaCO ₃ + SO ₃ + ½O ₂ → CaSO ₄ + CO ₂ At this time, in the preheating process, the mixed material emits exhaust gas through the chemical reaction process with the limestone material as described above. The spray tower of sprays 20 tons of water per hour, where the hydrophilic harmful gases such as HCl, SO ₂ , NO _x , and CO in the exhaust gas passing through the spray tower are dropleted together with dust and are not released into the atmosphere. This prevents secondary pollution such as air pollution. The pre-heated blended raw materials are fed back into the kiln and fired at 1450-1500 ° C. to produce clinkers. On the other hand, Table 4 shows the results of analyzing the quality of the cement produced by the present invention.

The present invention implements a method for recycling dust and waste sludge of steelmaking as a cement raw material can create economic and environmental benefits from the recycling of waste, can bring down the cost of cement, during the manufacturing process It provides an effect that does not cause any environmental pollution at all.

Claims (3)

In the manufacturing method of cement for mixing and grinding limestone, clay material, iron oxide raw material and the like, after producing the clinker through preheating of the preheater and firing of the kiln, and then grinding with gypsum in the grinder to produce cement, Mixing 2% by weight of inorganic sludge in the wastewater mixed with limestone powder and 2% by weight of dust in steelmaking together with 96% by weight of raw materials such as limestone; Preheating to 800-900 ° C. in a preheater; Firing at 1450 ~ 1500 ℃ in the kiln; manufacturing method of cement using sludge of the dust and waste water of steelmaking. delete delete