KR20000075373A - A method for manufacturing nomal potland cement utilizing a sewage and clean water sludge - Google Patents

Abstract

PURPOSE: A conventional portland cement using sludge as raw materials is provided to save manufacturing costs and prevent environmental pollution. CONSTITUTION: The manufacturing method of portland cement comprises the steps of: mixing sludge as clay materials with lime and other materials; grinding to a size of smaller than 100 micrometer; heating to 1500°C for purifying and producing clinker; quenching to lower than 100°C; adding gypsum, then grinding.

Description

A method for manufacturing nomal potland cement utilizing a sewage and clean water sludge as raw material for sewage and purified sludge

The present invention relates to a conventional portland cement and its manufacturing method using sewage and water purification waste, and in particular, by manufacturing a large amount of sewage and purified water sludge produced during sewage and water purification as raw materials for portland cement. It relates to ordinary portland cement utilizing sewage and water purification sludge, as well as savings, which can prevent serious environmental pollution from sewage and water purification wastes, and methods of manufacturing the same.

Economic development and improved living have resulted in pollution of drinking water sources, and thus, the facilities of sewage and water treatment plants and sewage treatment plants have been inevitably increased. Therefore, the amount of sludge, which is a secondary by-product generated in sewage and water treatment, is also gradually increased, and its treatment is a big environmental problem.

At present, the treatment of these sludges depends on methods such as ocean dumping and landfilling. However, marine dumping has many problems in the process of managing, storing, and transporting the sludge to the ocean, and since dumping of waste has been banned worldwide since 1996 under the London Convention, sludge dumping at sea Is also expected to be regulated in the near future.

On the other hand, there is another method of simple incineration after drying, but the high incineration cost and the treatment of ash generated after incineration has become a problem. This ash is usually mixed with solidifying agents such as Portland cement, but it is not suitable for the situation where landfill is insufficient as domestic situation because the volume of waste generated at that time becomes large.

Therefore, it is well known that the disposal of waste is now a serious social problem that threatens the living environment and the global environment. Therefore, it is now desirable to find a way to reduce secondary pollutants generated during the treatment by actively utilizing the simple treatment step of the sludge causing the above problems.

In particular, among the wastes generated in our daily life, the purified sludges generated during the purification of drinking water sources closely related to our lives and the sewage sludges generated after sewage treatment have reached the limit in reality, but the amount of wastes is increasing. It is causing environmental pollution.

Such sewage and water purification sludge are discarded as it is, so it is a big loss in terms of economics, and the use of this as a resource is an innovative way to prevent economic pollution and simultaneously meet the economic benefits of resource recycling.

In view of the above, SiO ₂ , Al ₂ O ₃ , and Fe ₂ O ₃ , which are the main components of sewage and water purification sludge, are usually used as raw materials for portland cement. A method of stably treating sewage and purified sludge by purifying the harmful components of sewage and purified sludge in the process of heating to 1500 ℃. This is the best way to prevent national economic benefits and environmental pollution.

An object of the present invention is devised in view of the above, by using a large amount of sewage and purified water sludge produced in the purification of drinking water as a raw material of cement to reduce the manufacturing cost of cement as well as to reduce the production cost of cement as well as sewage and water purification It is to provide ordinary Portland cement and ordinary Portland cement manufacturing method using sewage and water sludge which can prevent serious environmental pollution caused by waste.

1 is an overall schematic diagram of a cement manufacturing facility for explaining the ordinary portland cement manufacturing process utilizing sewage and water purification sludge according to the present invention,

Figure 2 is a flow chart showing the process of Figure 1 clearly;

3 is a layout view of the cement production facility to which the present invention is applied.

* Explanation of Signs of Major Parts of Drawings *

10: 1st crusher 12: Limestone primary mixing fixture

14: secondary crusher 16: third crusher

18: limestone secondary mixing fixture 20: raw material storage

22: raw material grinding machine 24: mixed raw material storage room

26: preheater 28: firing furnace

30: cooler 32: clinker reservoir

34: cement grinding machine 36: cement storage

38: packing machine 40: spray tower

50: electrostatic precipitator

Portland cement manufacturing method using the sewage and water purification sludge according to the present invention for achieving the above object in the method of manufacturing cement, sewage and purified water sludge supplied from the sewage treatment plant and water purification plant as a clay raw material Mixing with calcareous and other minor ingredients; Grinding the mixed raw material to a size of about 100 μm or less; Heating the pulverized raw material up to 1500 ° C. to purify harmful components contained in sewage and water purification sludge and to produce clinker, which is usually an intermediate product of Portland cement; And clinker as a main raw material, and mixing and pulverizing gypsum as an additive thereto to produce the final product, ordinary portland cement.

In addition, the ordinary portland cement prepared by utilizing the sewage and purified water sludge according to the present invention for achieving the other object is a common portland cement manufactured by mixing lime material, clay material with gypsum, sewage and purified water sludge It is characterized in that it is prepared by mixing with the lime raw material and the secondary raw material as the clay raw material to produce a combination raw material and adding the gypsum as an additive.

In general, Portland cement is mainly composed of compounds such as SiO ₂ , Al ₂ O ₃ , Fe ₂ O ₃ and CaO. Its quality characteristics must be within a certain standard. It should be tempered. In order to manufacture such ordinary portland cement, it is necessary to select raw materials containing SiO ₂ , Al ₂ O ₃ , Fe ₂ O _3, and CaO, which are the main components of the ordinary portland cement. have.

First, it is a raw material for calcite, accounting for about 60 ~ 66% of Portland cement.

Second, clay raw materials are obtained from clay which is widely distributed on the surface, and other SiO ₂ , Al ₂ O ₃ and Fe ₂ O ₃ are covered from clay raw materials except CaO, which is a basic component of Portland cement. As a raw material for portland cement, clay is less than 55% of SiO ₂ and more than 20% of Al ₂ O ₃ , and the lower the alkali content (Na2O + K2O) is the main factor in forming the coating of the kiln, the lower the quality of clay The blending ratio is around 10%. In the present invention, the clay raw material is used to replace sewage and purified sludge with existing clay or pumice, pavement and fly ash. For this reason, the raw material cost can be reduced.

Third, iron oxide is usually used when lime and clay materials do not meet Fe ₂ O ₃ content, which is about 3-4% of Portland cement.

Fourth, gypsum is a raw material added to semi-finished clinker which is usually fired to control the setting time of Portland cement. It is used to improve initial strength, reduce underwater expansion and shrinkage, and improve stability. The gypsum content is usually about 4-5% of Portland cement.

The general Portland cement manufacturing method using sewage and water purification sludge as a clay material in ordinary Portland cement having the above raw material composition is as follows.

The method of treating sewage and purified sludge generated in the sewage and purified water treatment process at each sewage treatment plant and water purification plant is not covered in the present invention. However, the present invention is to disclose a method of using the sewage and purified water sludge generated in the sewage and water treatment process as a clay material of the ordinary portland cement.

When sewage and purified water sludge is transported from each sewage treatment plant and water purification plant, sewage and purified sludge supplied from each sewage treatment plant and water treatment plant is mixed with lime and other auxiliary materials. Then, the mixed raw material is ground to a size of about 100 μm or less. The ground material is heated up to 1500 ° C to produce clinker, an intermediate product of cement. In this process, noxious components are purified to harmless components. Then, using the clinker as an intermediate product as the main raw material, the gypsum as an additive is mixed and pulverized. The final product, usually Portland cement, is then produced.

Hereinafter, with reference to the accompanying drawings will be described in detail for the ordinary portland cement manufacturing method utilizing sewage and water purification sludge according to the present invention.

Figure 1 is a general schematic diagram of a typical Portland cement manufacturing facility for explaining the ordinary Portland cement manufacturing process utilizing sewage and water purification sludge according to the present invention, Figure 2 is a flow diagram showing the process of FIG. In addition, Figure 3 shows a layout of a normal portland cement production equipment to which the present invention is applied.

Limestone mined from the limestone mine is subjected to the primary crusher (10), the limestone primary mixed fixture (12), the secondary crusher (14), the tertiary crusher (16), and the limestone secondary mixed fixture (18). While being ground to a size of 30 mm The crushed limestone, clay material and iron oxide material are stored and mixed in the raw material storage unit 20 and sent to the raw material grinding machine 22 to pulverize the mixed raw material to a size of about 100 μm or less. At this time, the sewage and purified sludge transported to the sewage treatment plant and water purification plant will be used as clay raw material. (Step 100, 110) This finely ground raw material is stored in a large cylindrical mixed raw material storage room 24, and a predetermined amount is Supply to the process. Prior to inputting the pulverized ordinary Portland cement raw material into the kiln, which is the main heating furnace, the preheater 26 is preheated to about 900 ° C. to increase thermal efficiency and productivity. At this time, limestone is actively decomposed into CaO and CO ₂ in the temperature range of about 800 ~ 900 ℃. The decomposed lime (CaO) component is purified into harmless components by reacting with harmful gases such as HCl and SO ₂ generated during incineration of waste, and the reaction formula is as follows.

CaCO ₃ → CaO + CO ₂

CaO + 2HCl → CaCl ₂ + HCl

CaCO ₃ + SO ₃ → 1 / 2O ₂ → CaSO ₄ + CO ₂

In particular, the exhaust gas purified as a harmless gas by the chemical reaction with the raw material as described above while passing through the preheater 26 is introduced into the spray tower 40 of the dust collecting facility shown in Figure 3, the spray tower 40 In Esau, about 20 tons of water are injected per hour to form hazardous particles with dust. This utilizes the property that the harmful gases HCl, SO ₂ , NOx, CO, etc. in the exhaust gas is well dissolved or absorbed in water. Thus dissolved or absorbed harmful gas and droplets of the particles are collected while passing through the electrostatic precipitator (50). Therefore, the harmful gases generated during incineration of waste are significantly reduced in concentration and are exhausted through the chimney.

On the other hand, the raw material first heated in the preheater 26 is heated and fired to a maximum temperature of 1500 ° C. in the kiln 28 to produce a clinker, which is usually an intermediate product of Portland cement. (Step 120) The high temperature clinker discharged from the kiln 28. It is sent to the cooler 30 to quench below 100 ° C. The clinker, which is then cooled to the clinker reservoir 32, is stored and supplied to the portland cement grinder 34, usually by an amount. In this way, the clinker supplied as a main raw material is mixed with the gypsum as an additive in the ordinary Portland cement grinder 34 to finely grind the final product to produce the final portland cement. (Step 130) The produced ordinary portland cement is usually stored in portland cement. It is stored in the machine 36 and shipped through the packaging machine 38 or shipped in bulk (Bulk) form.

Hereinafter will be described in detail with respect to the effect of the present invention.

In the above manufacturing process, since clay material takes up about 10% of the ordinary portland cement raw materials, sewage and water purification sludge can be used up to 10% in ordinary Portland cement production, but it is not practically possible due to quality problems. In fact, up to about 3% can be used when used with pumice, feldspar, and fly ash, and up to 5% when using the above raw materials.

Table 1. Review of Sludge Chemical Composition

(unit : % )

ingredient SiO2 Al2O3 Na2O + K2O CI (PPM) Reference value 55 ↓ 20 ↑ 4 ↓ 300 ↓ A water purification plant 45.74 24.93 3.60 248 B water purification plant 34.04 29.23 2.45 938 C water purification plant 45.98 25.04 4.10 53 D water purification plant 50.26 21.25 - 13 E water purification plant 47.74 19.45 - 33 Average 44.75 23.98 2.03 257

Table 1 shows the chemical composition table of the purified sludge transported from each water treatment plant, showing that the chemical composition of the purified sludge supplied from each water treatment plant is suitable for the standard value required for the clay material of ordinary Portland cement described above. have.

Table 2. Raw Material Composition Ratio

(unit : %)

division L.S.F S.M I.M Standard of use 93.0 ± 1.0 2.48 ± 0.05 1.65 ± 0.05 2% raw materials 94.0 2.55 1.63 3% raw materials 94.8 2.56 1.60

Here, L.S.F represents the degree of lime saturation (LIME SATURATION FACTOR), S.M represents the SILICA MODULUS, I.M represents the iron modulus (IRON MODULUS). As shown in Table 2 above, it is confirmed that there is no problem in the use of purified sludge within 3%, since the purified sludge use amount satisfies the usage criteria up to 3% of the total raw material input amount.

Table 3. Common Portland Cement Quality Review

(Unit:%, ㎠ / g, kgf / ㎠)

Date Chemical composition Physical performance MgO 1g Loss Powder 3 days strength 7 days strength 28 days strength KS Standard 5.0 3.0 2800 130 200 290 October 27 2.57 1.30 3441 220 313 404 October 28 2.53 1.25 3347 230 300 410 October 29 2.54 1.31 3275 226 307 408 October 30 2.50 1.29 3326 235 312 408 October 31 2.59 1.32 3388 230 300 392 November 2 2.56 1.36 3372 233 310 410 November 3 2.58 1.25 3340 230 310 412 November 4 2.66 1.41 3356 224 304 410 5 November 2.61 1.42 3325 238 307 408 November 6 2.61 1.38 3351 237 301 410 Average 2.58 1.33 3352 230 306 407

Table 3 shows the results of ordinary Portland cement production using the water sludge transported from each water treatment plant as clay material. According to this table, the quality of ordinary portland cement produced using purified water sludge meets the KS standard in terms of chemical composition and physical performance, and it is proved to be inferior to conventional portland cement produced using conventional clay or other materials. .

Table 4. Review of Sewage Sludge Chemical Composition

(unit : % )

ingredient SiO2 Al2O3 Na2O + K2O CI (PPM) Reference value 55 ↓ 20 ↑ 4 ↓ 300 ↓ A Sewage Treatment Plant 36.21 21.59 2.67 283 B sewage treatment plant 32.78 23.72 2.22 248 C sewage treatment plant 32.09 23.88 2.95 283 D sewage treatment plant 39.13 20.23 2.29 319 E Sewage Treatment Plant 37.20 21.08 1.82 212 Average 35.48 22.10 2.39 269

Table 4 shows the chemical composition table of the sewage sludge transported from each sewage treatment plant, and the chemical composition of sewage sludge supplied from each sewage treatment plant is suitable for the standard requirements for clay material of ordinary Portland cement described above. Is showing.

Table 5. Raw Material Composition Ratio

(unit : %)

division L.S.F S.M I.M Standard of use 93.0 ± 1.0 2.48 ± 0.05 1.65 ± 0.05 2% raw materials 93.8 2.50 1.66 3% raw materials 94.0 2.51 1.64

Here, L.S.F represents the degree of lime saturation (LIME SATURATION FACTOR), S.M represents the SILICA MODULUS, I.M represents the iron modulus (IRON MODULUS). As shown in Table 5 above, it is confirmed that there is no problem in the use of sewage sludge within 3% because the usage of sewage sludge meets the usage criteria up to 3% of the total input of raw materials.

Table 6. Moderate Portland Cement Quality Review

(Unit:%, ㎠ / g, kgf / ㎠)

Date Chemical composition Physical performance MgO 1g Loss Powder 3 days strength 7 days strength 28 days strength KS Standard 5.0 3.0 2800 130 200 290 October 27 2.87 1.36 3382 234 302 406 October 28 2.92 1.22 3342 232 302 402 October 29 2.88 1.31 3398 230 299 398 October 30 2.81 1.26 3410 238 320 408 October 31 2.74 1.42 3451 216 298 389 November 2 2.81 1.28 3427 223 305 400 November 3 2.73 1.12 3373 223 299 400 November 4 2.83 1.31 3407 233 306 403 5 November 2.73 1.28 3328 224 309 397 November 6 2.72 1.44 3352 222 304 400 Average 2.80 1.30 3387 228 304 400

Table 6 shows the results of ordinary Portland cement production using the sludge transported from each of the above sewage treatment plants as clay raw material. According to this table, the quality of ordinary Portland cement produced using sewage sludge meets the KS standard in terms of chemical composition and physical performance, and it is proved to be inferior to conventional Portland cement produced using conventional clay or other materials. .

As described above, the ordinary portland cement manufacturing method utilizing sewage and purified water sludge according to the present invention is usually recycled by recycling a large amount of purified sludge generated during drinking water purification and sewage sludge produced by sewage treatment as a raw material of portland cement. It has the advantage of reducing the manufacturing cost of Portland cement and improving the competitiveness of the manufacturing company. In addition, by recycling the sewage and purified water as resources, not only can the waste disposal cost be reduced, but it also has the effect of contributing to the protection of the global environment by preventing serious environmental pollution caused by sewage and purified water waste.

Claims (5)

Usually in Portland cement, Portland cement, usually made from sewage and purified sludge, characterized in that the clay raw material is water treatment sludge. 2. The ordinary portland cement according to claim 1, wherein the sewage sludge is a sewage sludge. 2. The ordinary portland cement according to claim 1, wherein the water treatment sludge is purified water sludge. Usually in Portland cement manufacturing methods, Mixing the water-treated sludge as a clay material and mixing it with lime and other auxiliary materials; Grinding the mixed raw material to a size of about 100 μm or less; Heating the pulverized raw material up to 1500 ° C. to produce clinker, an intermediate product of cement; And The main portland cement manufacturing method using the sewage and water purification sludge, comprising the step of mixing the finer gypsum as the main raw material and grinding and grinding the gypsum as an additive. [5] The method of claim 4, wherein the hazardous ingredients are purified as harmless components by heating the pulverized raw materials up to 1500 ° C.