KR20090128000A - Manufacturing method of lightweight bricks by using sludge - Google Patents

Abstract

PURPOSE: A method for manufacturing a lightweight brick is provided to recycle waste effectively by using sludge and to lower the cost with obtaining a high quality. CONSTITUTION: A method for manufacturing a lightweight brick comprises the steps of (10) drying the material comprising sludge, clay and silica; (20) pulverizing the material; (30) mixing the material comprising sludge, clay and silica; (40) molding a brick; (50) drying the brick at a low temperature; and (60) sintering the brick at a high temperature and cooling the sintered brick.

Description

Manufacturing Method of Lightweight Bricks by Using Sludge}

The present invention relates to a method for producing lightweight bricks using sewage sludge and wastewater sludge, and more particularly, to produce lightweight bricks using sludge, and to efficiently recycle wastes, and at the same time, to use low cost wastes. The present invention relates to a method for manufacturing lightweight brick using sludge, which can produce high quality lightweight brick at a cost of iii).

In general, sludge treatment in the water purification process consists of four stages: adjustment, concentration, dewatering and disposal. The amount and quality of sludge vary depending on the purification facility and its operation. The adjustment process adjusts chemicals and sludge concentration, and the concentration process increases the sludge concentration to make it easier to dehydrate. In the dehydration process, water is removed from the concentrated sludge in the concentration facility and made to be easily disposed of. It is made of 8% or more (usually 10-20%) based on the weight of solids, and there are two methods of using nature and a method of dehydration in a dehydration facility. The drying process is a process for making 35% or more based on the solids content, and the disposal process is a process to convey the generated cake by dumping or using it for a special purpose.

Sludge (sludge) includes sludge generated during dehydration after water treatment and process sludge generated during product manufacturing. Waste management legislation requires that sludge be classified only if the moisture content is less than 95% or the solids content is more than 5%. Inorganic sludge from general water purification facilities is dehydrated and dried to less than 70 percent water content.

As such, the sludge generated in the water purification process is generated when backwashing the sediment deposited in the sedimentation basin and the suspended substances held in the filter paper. The sludge generated in the sedimentation basin and the filter paper is disposed of after the concentration and dehydration treatment. The sludge produced in the water treatment facility has the characteristics similar to clay in the soil classification, and is used for the cover of soil, auxiliary base material, road base material and landfill facility in construction and civil works.

In this case, inorganic sludge generated from water purification facilities for water works should be dehydrated and dried to 70% or less of water content, and mixed with more than 50% by volume of soil collected from recycled general soil or construction waste products. In addition, it is attempting to apply sludge to earthworks, ceramics, and soft materials.

The sludge of the water purification plant as described above is an inorganic sludge, which is composed of components other than organic sludge, which is a sludge for sewage treatment plant, and is converted to landfill in the metropolitan area despite relatively low pollution. And recycled as cover material. Such sludge is landfilled by mixing with construction wastes without going through special intermediate treatment process, and complaints have been raised to bury wastes such as secondary groundwater pollution or waste due to accumulated leachate. Not only does this increase, there is a problem in that the processing cost increases.

On the other hand, a very large amount of waste is produced by a chemical process used for water treatment in a water treatment plant. The remaining wastes contain organic and inorganic wastes, and the water treatment sludge contains concentrated metals such as pathogenic microorganisms (bacteria, viruses, protozoa), organic compounds containing halogen elements, aluminum and iron.

In most countries, sludge from water treatment plants is dewatered and treated before being discharged into the water environment system. Eventually, no matter what treatment, sludges from the water treatment plant will load contaminants into the surface water. They also put loads on sewage treatment plants and the land, sometimes reprocessing the sludge to reuse the sludge.

Such sludges may be used for agriculture depending on their physical and chemical properties, and may be used for recovery of aluminum usable as a flocculant or for phosphorus control in wastewater treatment facilities. However, effluents containing sludge from untreated or untreated water can reach the water environment, causing toxicity to aquatic organisms and degrading the quality of the water environment system. The most important factor entering the water environment from sludge from water treatment plants is the toxic potential of iron and aluminum.

As the purified sludge generated in the water treatment process contains harmful components, the disposal by simple landfill by mixing with construction wastes without going through a special intermediate treatment process is accumulated in the natural world due to the leachate of the landfilled waste. It can have a negative impact on the groundwater pollution or the ecosystem.

Therefore, there is an urgent need in the art to develop a technology that can be recycled using such sludge and that can be stabilized and harmless rather than landfilled.

The present invention is to solve the conventional problems as described above, the purpose is to produce a light-weight brick using sludge can not only effectively recycle waste, but also to be stabilized and harmless treatment rather than landfill treatment The present invention provides a method for manufacturing lightweight brick using sludge.

And another object of the present invention is to provide a light-weight brick manufacturing method using the sludge was able to produce a high-quality light weight brick at a low cost using the sludge waste.

In order to achieve the above object, the present invention, in the method for producing a lightweight brick using sludge,

Drying the raw material consisting of sludge, clay and silica sand;

Crushing the raw material;

Mixing the raw material consisting of sludge, clay and silica sand;

Forming bricks;

Low temperature drying of the bricks; And

It provides a method for producing a light weight brick using sludge; comprising the step of producing by cooling and cooling the brick to a high temperature.

In addition, the present invention is preferably the step of drying the raw material is a low-temperature drying of the purified sludge at 40 ℃ ~ 50 ℃, sewage sludge is characterized in that to remove the odor gas of the sludge by drying at high temperature from 800 ℃ to 1000 ℃ Provided is a method for manufacturing lightweight brick using sludge.

And the present invention preferably the step of mixing the raw material is 10% by weight to 40% by weight, 30% by weight to 70% by weight of clay, 30% by weight of silica sand 17% by weight to 25% by weight of water It provides a lightweight brick manufacturing method using the sludge, characterized in that the supply.

In another aspect, the present invention preferably provides a method for producing a light brick using sludge, characterized in that the step of mixing the raw material is made by further mixing any one of styrofoam, phage or sawdust as a pore material.

And the present invention is preferably a step of mixing the raw material is supplied with 17% by weight of water to the raw material of 10% by weight of sludge, 60% by weight of clay, 30% by weight of silica sand, 5 to 15 volumes relative to the raw material as a pore material It provides a lightweight brick manufacturing method using sludge, characterized in that the mixture is made of styrofoam in% ratio.

In another aspect, the present invention preferably provides a method for producing a lightweight brick using sludge, characterized in that the step of mixing the raw material is to mix the styrofoam in 5% by volume relative to the raw material as a pore material.

And the present invention preferably provides a method for producing a lightweight brick using sludge, characterized in that the step of mixing the raw material is using a sawdust as a pore material, 5% by volume relative to the raw material.

In another aspect, the present invention preferably comprises the step of drying the brick at a low temperature, the method of manufacturing a lightweight brick using sludge, characterized in that after drying at room temperature at 20 ℃ ~ 40 ℃, completely dried for 48 hours in a dryer of 60 ℃ ~ 70 ℃ To provide.

In the present invention, the step of firing the brick is preferably carried out by heating at 500 ° C. in a kiln for 2 hours, and then firing it first, and heating from 500 ° C. to 800 ° C. for 2 hours, second firing It is heated to 1100 ℃ to maintain for 2 hours to provide a method for producing a lightweight brick using sludge, characterized in that the third firing, and then cooled in a kiln.

In addition, the present invention is preferably the step of firing the brick is cooled to 1100 ℃ to 300 ℃, at 300 ℃ to open the door of the kiln 20%, at 200 ℃ to open the door of the kiln 40% to open the kiln door It provides a lightweight brick manufacturing method using the sludge, characterized in that it is left open enough to supply air through.

According to the present invention, by producing lightweight bricks using sewage sludge and wastewater sludge, not only can the waste be efficiently recycled, but also the stabilization and detoxification treatment instead of landfill treatment can minimize the environmental pollution. Can be obtained.

In addition, according to the present invention, it is possible to produce high-quality lightweight bricks at low cost using sludge waste, thereby obtaining an excellent effect that enables various utilization of resources.

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

Light brick manufacturing method (1) using the sludge according to the present invention, as shown in Figure 1, the first step of drying the raw material is made (10). As raw materials, sludge composed of sewage sludge or purified sludge, clay and silica sand are used, and these are dried at high temperature. Here, the sludge is used to collect sewage sludge with a water content of 80% or more and purified sludge with a water content of 30% or more, which is to collect dewatered sludge from sewage treatment plants and water treatment plants. In addition, the dewatered sludge is dried as described above, wherein the purified sludge is dried at a low temperature at 40 ° C. to 50 ° C., and the sewage sludge is dried at a high temperature at 800 ° C. to 1000 ° C. to remove the odor gas. When it is dried, the generation of malodorous gas can be reduced, and it is completely dried in this manner to zero the sludge moisture content.

Then, the step 20 of crushing the raw material is made. In the crushing step 20, when the clay and silica sand are dried and then crushed in a round roller, etc., the crushing is generally performed well, and the purified sludge is crushed by passing through a crusher after drying, and then sludge, clay and silica sand are crushed. Each of the mesh (mesh) is passed through 18 to sieve to prepare.

In addition, the present invention comprises the step 30 of mixing the raw material consisting of the sludge, clay and silica sand. The mixing step 30 of the raw material is 10% by weight to 40% by weight, 30% by weight to 70% by weight of clay, 30% by weight of silica sand as a raw material, and any one of styrofoam, phage or sawdust as a pore material 17 to 25% by weight of water is supplied and mixed. When dry sludge, clay, silica sand, and pore-forming agent are mixed in each ratio and water is mixed in an amount of about 17 wt% to 25 wt%, the amount of water injected increases as the amount of sludge injected into the raw material increases. As the sludge injection volume increases, the volume also increases.

And the raw material as described above can be made lightweight by mixing the pore material, but any one of styrofoam, phage or sawdust can be used as the pore material, preferably the pore material is mixed with styrofoam at a ratio of 5 to 15% by volume. In this case, the pore materials such as styrofoam or phage and sawdust are calculated by volume (volume) ratio because of their very small specific gravity, and the remaining sludge, clay and silica sand are mixed by weight ratio. The styrofoam used as the pore material is expandable polystyrene having a small particle size.

The main components of the clay used above are silicic acid (SiO 2: 50% to 70%) and alumina (Al 2 O 3: 36 to 15%), and others include Fe 2 O 3, CaO, MgO, K 2 O, Na 2 O 3, and the like. Clays containing a lot of silicic acid have good plasticity, but if there are more components other than the main component, the softening temperature is lowered and the plastic deformation is increased, so that a good product cannot be produced. Chemically pure clay is called kaolin, and the baked clay powder is called chamotte. The specific gravity of clay is 2.5-2.6 and the particle size is usually 2μ or less, but it contains a little bit of sand grain. Plasticity is an important property in clay molding. The higher quality clay is, the better plasticity is, and when plasticity is too large, it is controlled by mixing a dedusting agent such as sand or chamotte.

The porosity is expressed as a percentage of the total volume of clay and is 30% to 90%, on average about 50%, and the water content is 7 to 10% for the small ones and 40 to 50% for the large ones. Tensile strength is greatly affected by the type of clay, particle size, and the like. The tensile strength of fine clay is 3 ~ 10kg / cm2 and the compressive strength is about 5 times the tensile strength.

As such, when the clay is molded and dried, a part of the moistened moisture is released and shrinkage occurs. The shrinkage of the length of drying ranges from about 5 to 6% to about 10 to 15% and almost three times its volume. In addition, shrinkage occurs during firing. Plastic shrinkage is related to the amount of volatile matter (bonded water, organic matter, carbon dioxide, etc.) contained in the clay, the structure of the clay, and the degree of melting. When the clay is fired, some or most of the contained components are dissolved to cause changes in volume, specific gravity, color tone, and the like, and the strength is significantly increased by close contact with each other with cooling.

Then, after the step 30 of mixing the raw materials, a step of forming a brick 40 is performed, and the step of forming the brick 40 is performed by mixing and kneading the raw material of the brick standard molding machine (not shown). ) To cover the lid evenly, and then compression molding by applying a pressure of about 3kg / ㎠ through a compression molding machine. Thus, the step 40 of forming the brick may be performed by using a conventional brick compression molding machine.

In addition, a low temperature drying step 50 of the brick compression-molded in the shape of a brick is performed next. As such, the step 50 of drying the bricks at low temperature is first drying the bricks at room temperature for a predetermined time and then completely drying them in a dryer. The drying step at room temperature is followed by drying at 20 ° C. to 40 ° C. for a predetermined time, and then 60 ° C. to 70 ° C. Complete drying for 48 hours in a dryer at ℃. Thus, when dried at room temperature, the brick surface is gradually dried so that the surface of the brick is not cracked, but if the high temperature drying is carried out without going through the room temperature drying, the surface crack occurs while the moisture contained in the brick is dried within a short time. Therefore, first drying slowly at room temperature, and then completely dried by raising the temperature in the dryer, it is well dried without cracking on the surface of the brick.

Next, a step 60 of producing and cooling the brick to a high temperature is made. In the firing step 60, the brick is heated to 500 ° C. in the kiln and maintained for 2 hours, and then fired. The brick is heated from 500 ° C. to 800 ° C. and maintained for 2 hours. It is heated to ℃ and maintained for 2 hours to be calcined tertiary, and then allowed to cool in a kiln.

In addition, the cooling step 60 made after firing the bricks as described above is cooled to 1100 ° C to 300 ° C, and at 300 ° C, the door of the kiln is opened by 20%, so that the air is supplied through the kiln door, At 200 ° C, 40% of the doors of the kiln are left open. The reason why the door is opened about 20% at 300 ° C. in the cooling process is that this section is the section that most affects the strength. This is because if the door of the kiln is opened at 300 ° C to supply oxygen, it affects the color of clay brick and the surface luster and also affects the strength.

On the other hand, if the brick is not sufficiently dried in advance in the firing step 60, for example, the proper water content is less than 2%, the surface is calcined first during the firing process, so that a small amount of moisture and air in the brick cannot escape. As a result, cracks appear on the surface and are poorly treated. The lightweight bricks, which have been calcined and cooled in this way, are withdrawn from the kiln and collected and shipped.

Hereinafter, a series of experiments were carried out on the light bricks obtained through the light brick manufacturing method (1) using the sludge of the present invention, and it was determined whether it conformed to the standard specification.

The sludge used as raw material in the manufacturing method of light brick using sludge of the present invention (1) was extracted from the dehydration cake, the final process of water treatment, from the hopper as a storage facility, and clay and silica sand (raw sand) were used as raw materials for manufacturing red brick. .

The water content of the purified water sludge used in the sludge production method (1) using the sludge of the present invention was 32.39%, loss of ignition 21.22%, solids 43.54%, organic matter content 0.59%, specific gravity was 1, clay The water content of was 16.68%, loss of ignition 5.21%, solids 83.32%, organic matter content 0.27%, specific gravity 1.8.

In addition, the dissolution test on the purified sludge and clay used in this experiment was conducted to analyze the dissolution characteristics of heavy metals and to examine the results. Heavy metals and harmful substances were analyzed by eluting with purified sludge and clay TCLP method. In analysis sludge (Pb, Cu, As, Hg, Cd, Cr + 6, CN, organophosphorus, TCE, PCE), As (0.107 mg / l), Cd (0.084 mg / l) in clay sludge, As (in clay) 0.105 mg / l), Cd (0.084 mg / l), etc. were detected, but did not reach the reference concentration of heavy metals. The remaining items were not detected.

Purified sludge used for producing lightweight bricks according to the method for producing light bricks using sludge of the present invention is natural drying and after drying at 40 ° C. to 50 ° C. in a dryer 12 as shown in FIG. 2. It was used by crushing and passing the mesh No. 18.

In this process, when the clay is crushed with a round roller after drying, the crushing is generally well done. However, the purified sludge is not crushed by the rollers like clay, so that a separate crusher (not shown) is used. Crushed and sieved through a mesh 18 sieve 15 as shown in Figure 3a).

And supplying 17% by weight of moisture to the raw material 25 consisting of the sludge, clay and silica sand, as shown in Figure 3b), the pore material 22 is a styrofoam, phage, sawdust at least 5 volumes each Mix up to 15 vol% in volume. After mixing and kneading the sample evenly in the molding machine 32 as shown in Figure 3c of the brick standard, cover the lid, and then beat several times with a rubber mallet, a compression molding machine (model number Kyeong Do Model KDC-C12) ( 34) to apply a pressure of about 3kg / ㎠ to form a light brick.

The lightweight brick 55 manufactured as described above was manufactured as a real brick standard of 190mm × 90mm × 57mm rectangle, as shown in FIG. 3d), and after the molding was completed, after natural drying for about 4 hours, 60 Drying was completely completed for 48 hours in a dryer of ℃ ~ 70 ℃ to prepare for firing.

Next, as shown in FIG. 3E), the brick was calcined in the kiln 62. In this firing process, first, the brick 55 in the kiln 62 is heated to 500 ° C. and maintained for 2 hours, and then calcined first, then heated to 500 ° C. from 800 ° C. to 800 ° C. for 2 hours, and then calcined. The mixture was heated from 800 deg. C to 1100 deg. C, held for 2 hours, and then calcined in a calcination furnace 62. In this cooling process, the mixture is allowed to cool from 1100 ° C to 300 ° C. At 300 ° C, the door of the kiln is opened by 20%, and the air is supplied to the air through the kiln door. 40% open.

In this way, a lightweight brick 55 of 190 mm × 90 mm × 57 mm rectangular size, which is the actual brick standard, was manufactured. A number of such bricks were manufactured while varying the ratio of clay and water purification sludge, and their respective compressive strengths and absorption ratios. , Weight reduction rate and heavy metal dissolution characteristics were tested.

Compressive strength test

The specimens used in the test were molded into a 190mm × 90mm × 57mm rectangle, which is the actual brick standard, and the strength after firing was measured. The uniaxial compression test of soil is carried out by compressing and breaking the viscous soil in the natural state and in the direction of re-molded lightweight brick (55). In this process, the load according to the axial deformation is measured to draw the strain-stress relationship. The strength was obtained.

The compressive strength of the solids was carried out using a Digital Concrete Compression Strength Tester (HS-1471) (not shown).

The digital concrete compressive strength tester used for measuring the compressive strength is composed of digital electric type that can read various values immediately, and it can be attached to the recording device if necessary. When preparing various pressure plates, the brick, block, and bending strength test can be performed. It is made with One Touch Load Value. The specifications of the digital concrete compressive strength tester were as follows.

Model ( Model ) HS -1471 Motor Operation Electric drive method Max, Capacity 20 ton Min, Graduation 1 kg Upper and Lower Compression Distances (Between Columns) 160-350 mm Ram Stroke 25 mm Display Digital Display Digital Gauge Peak / Free Load Over Load Display Hydraulic Pump Rotary Plunger Pump Precision (Detailed Drawing) ± 1%

The experimental results thus measured are shown graphically in FIG. 4.

As a result of the measurement, the compressive strength of the lightweight brick 55 solidified by mixing the purified sludge, clay, and silica sand was measured. As a result, the compressive strength decreases as the injection amount of the hardener increases and the injection amount of the clay decreases. appear. However, at 60 wt% of clay and 10 wt% of purified water sludge, the highest value was 236.4Kg / cm2, and the grade 1 of clay brick was reached.

In order to reduce the weight, 5 ~ 15% by volume of pore agents (styrofoam, phage, sawdust) were injected into clay (70% by weight) and silica (30% by weight), and the compressive strength after firing was measured. The highest injection rate was 290.2Kg / cm2, and the clay brick quality standard 1 was reached.

In addition, when 5 to 15 vol% of pore agents were injected into clay (60 wt%), purified sludge (10 wt%) and silica sand (30 wt%), the strength was increased in the order of styrofoam >> sawdust >> phage. Compressive strength of solids was found to be 108.0 ~ 236.4Kg / cm2, the highest when the injection of 5% by volume of styrofoam was 236.4Kg / cm2, and 108.0Kg / cm2 when the injection of 15% by volume of sawdust. It did not meet the quality standards of clay bricks.

In addition, as the injection amount of clay (50% by weight) decreased and the injection amount of purified sludge (20% by weight) and the pore-agent increased, the compressive strength was lowered.

In addition, 10% by weight of pure sludge (40% by weight) is injected from clay (30% by weight), and 5 to 15% by volume of pore is injected to reduce the compressive strength to almost the quality standard of clay brick. It did not appear.

In the case of using styrofoam as a lightweighting agent, the compressive strength meets the brick standard when the sludge injection amount is within 10% by weight, but it does not have the compressive strength characteristics as a brick product when the sludge injection amount is 20% by weight or more. In addition, when the weight was used as a lightening agent, the compressive strength of the sludge injection amount up to 10% by weight satisfied the brick standard, but when the weight was 20% by weight, the brick standard was satisfied only when 5% by volume of the waste was added. And when 40% by weight of sludge is added, the strength of the brick standard cannot be obtained. On the other hand, when gripping was used as a lightening agent, the compressive strength of the sludge injection up to 10% by weight satisfied the brick standard. In addition, when 40% by weight of sludge is added, the strength of the brick standard cannot be obtained.

Water absorption test

Absorption rate experiment is performed through the following procedure. The lightweight block is dried in an air bath at 110 ± 5 ° C for 24 hours. After cooling to room temperature, it is weighed. Then, it is left to stand in water of 20 ± 5 ° C for 24 hours. Next, remove it from the water and quickly wipe the surface moisture with a damp cloth. Then measure the weight and calculate the absorption rate. Absorption rate calculation method is as follows.

a = (m2-m1) X 100 / m1

Where a = absorption (%)

m1 = weight of solid cooled to initial room temperature [dry weight (g)]

m2 = weight of solids after standing for 24 hours in water [weight including moisture (g)]

The experimental results thus measured are shown graphically in FIG. 5.

As a result of the measurement, the absorption rate of the light weight brick 55 solidified by mixing the purified sludge, clay, and silica sand was measured. As a result, the absorption rate of the purified sludge increased and the absorption rate increased as the amount of the injected clay decreased. .

In order to reduce weight, 5 vol% to 15 vol% of pore agents (styrofoam, phage, sawdust) were injected into clay (70 wt%) and silica sand (30 wt%), and the absorption rate after firing was measured. The highest was 12.1%. When injected by 5% by volume of sawdust, it was the lowest as 8.9% and reached the level 1 of clay brick quality.

In addition, when 5 to 15 vol% of pore agent was injected into clay (60 wt%), purified sludge (10 wt%) and silica sand (30 wt%), the absorption rate was in the order of styrofoam >> phage >> sawdust. The absorption rate of solids was 10.7% ~ 12.7%, 12.7% when 15 volume% styrofoam was injected, and the lowest was 10.8% when 5 volume% sawdust was injected. Reached the quality standard grade 2.

As the amount of injection of clay (50% by weight) decreased and the amount of purified sludge (20% by weight) and pore injection increased, the absorption rate increased.

In addition, 10% by weight of pure sludge (40% by weight) is injected from clay (30% by weight), and 5 to 10% by volume of pore-agent is lightened so that the absorption rate does not reach the quality standard of clay brick. Appeared.

On the other hand, when styrofoam is used as a lightening agent, when the sludge injection amount is within 10% by weight, the absorption rate is good, but when the amount is 20% by weight or more, the production potential of the product can be estimated according to the injection amount of the styrofoam. Moreover, if it is more than 40% by weight, it should not be considered as a product. In the case of using the phage as a lightening agent, the sludge injection amount is good up to 20% by weight, but when the amount is more than 40% by weight, the production potential can be estimated according to the injection amount of the phage. In addition, when sawdust is used as a lightening agent, it shows a similar pattern with phage, and the sludge injection amount is good up to 20% by weight, but when it is 40% by weight or more, the productivity of the sawdust can be estimated according to the injection amount of sawdust.

Weight reduction  exam

According to the present invention, the amount of porosity is generated according to the ratio of the styrofoam, phage and sawdust (5 vol% to 15 vol%) used as a pore agent by varying the injection amount of purified sludge and clay of the lightweight brick 55 manufactured according to the present invention. We looked at how lightweight the bricks are.

The experimental results of measuring the weight reduction rate are shown in a diagram in FIG. 6.

As a result of the measured results, the weight of the light brick (55) without sludge and pore weight was 1800.4g, and the light weight ratio of the light brick (55) fired by mixing 5% by volume to 15% by volume of each styrofoam, phage, and sawdust. This is shown graphically in FIG. 6.

In order to reduce the weight of the lightweight brick 55 manufactured according to the present invention, 5 to 15 volume% of the pore agent (styrofoam, phage, sawdust) is injected into clay (70 weight%) and silica sand (30 weight%). As a result of measuring the water absorption after firing, the light weight ratio of the light brick 55 was found to be at least 10.6% to 12.3%. However, even if the amount of the pore-forming agent is increased, the light weight rate is not significantly changed. It could be seen to be lighter.

In addition, the weight of the light brick (55), which is mixed with 10% by weight of sludge and does not contain a pore-forming agent, was 1812.2 g. ), The light weight ratio was at least 11.66% ~ 19.09%, but the weight ratio was not significantly changed even if the amount of pore was increased.

The weight of the light brick (55), which is mixed with 20% by weight of sludge and does not contain the pore-forming agent, was 1812.5 g, and the light bricks (5 to 15% by volume of each styrofoam, phage, and sawdust) were mixed in the same manner. ), The light weight ratio was at least 6.91% to 11.18%, but it was shown that the light weight ratio did not change significantly even if the amount of pore agent was increased.

On the other hand, the weight of the light brick (55), which is mixed with 40% by weight of sludge and does not contain the pore-forming agent, was 1806.3g, and the light brick (5 to 15% by volume of each styrofoam, phage, sawdust, etc.) was fired by mixing the same method. ), The light weight ratio was at least 5.15% to maximum 13.54%, but the increase in the amount of pore agent did not seem to change much, and the weight was reduced to around 10% on average.

Heavy Metal Dissolution Characteristic Test

Samples collected in the heavy metal dissolution test of the light brick 55 produced in accordance with the present invention usually contains organic matter and suspended substances, etc., which are not cloudy or colored, and the target components to be tested are adsorbed to the particles or hardly decomposable. Because they may exist in complex or complex ions, they should be pretreated by appropriate methods depending on the purpose of the test. In particular, a sample for measuring metal components is required to be pretreated to decompose organic matters, and reagents used for pretreatment should be those of high purity that do not contain the target component to be tested.

The pretreatment method of the sample by the waste process test method includes organic decomposition by nitric acid, organic decomposition by nitric acid-hydrochloric acid, organic decomposition by nitric acid-sulfuric acid, organic decomposition by nitric acid-perchloric acid, and nitric acid-perchloric acid-hydrofluoric acid. Organic decomposition and organic decomposition by incineration are available, but in this test, organic decomposition by nitric acid was used as pretreatment.

The organic decomposition method by nitric acid used in the test of the present invention is applied to a sample having a low organic content. Take an appropriate amount of liquid waste sample or eluent solution, place it in a Kjeldahl flask, add 5 ml of nitric acid and 4-5 glass spheres, and slowly heat to evaporate and cool until the liquid volume reaches about 5-10 mL. At this time, when the decomposition of organic matter is not completely clear, and the solution is not clear, add 5 ml of nitric acid and repeat the heating. If necessary, filter and wash the filter paper 2 ~ 3 times with water, and add the washed solution to make exactly 100 ml. The acid concentration of this solution is about 0.7N.

Heavy metals (Pb, Cu, As, Cd, Cr6 +) during the dissolution test of the present invention were analyzed according to the waste process test method of the Ministry of Environment Notice 2004-185 (2004.12.14). As an analytical method, Inductively Coupled Plasma (ICP) emission spectrophotometry (Perkin Elmer, USA) was used. Inductively coupled plasma emission spectroscopy is a qualitative and quantitative analysis of elements by injecting a sample into an argon plasma formed by a high frequency induction coil and measuring the emission line and emission intensity emitted when the excited atoms move from the 6,000 to 8,000 K to the ground state. It is a method to use.

The analysis method by item is as follows.

end. Pb ( Pb )

Pb is quantified according to inductively coupled plasma emission spectrophotometry. The quantitative range varies from 0.04 to 100 mg / l at 220.35 nm, depending on the equipment used and the measurement conditions. The emission intensity of the sample solution was measured at 220.35 nm according to the inductively coupled plasma emission spectrophotometry, and the concentration (mg / L) was calculated by calculating the amount of Pb from a calibration curve prepared in advance. Perform a background test to calibrate.

I. Cu ( Cu )

Cu is quantified according to inductively coupled plasma emission spectrophotometry. The quantitative range varies from 0.006 to 50 mg / l at 324.75 nm, depending on the equipment used and the measurement conditions. The emission intensity of the sample solution was measured at 324.75 nm according to the inductively coupled plasma emission spectrophotometry, and the concentration (mg / L) was calculated by calculating the amount of Cu from the calibration curve prepared in advance. Perform a background test to calibrate.

All. As ( As )

As is quantified according to inductively coupled plasma emission spectrophotometry. The quantitative range varies from 0.05 to 100 mg / l at 193.70 nm, depending on the equipment used and the measurement conditions. The luminous intensity of the sample solution was measured at 193.70 nm according to the inductively coupled plasma emission spectrophotometry, and the concentration (mg / L) was calculated from the calibration curve prepared in advance. Perform a background test to calibrate.

la. CD( CD )

Cd is quantified according to inductively coupled plasma emission spectrophotometry. The quantitative range varies from 0.004 to 50 mg / L at 226.50 nm, depending on the equipment used and the measurement conditions. The emission intensity of the sample solution was measured at 226.50 nm according to the inductively coupled plasma emission spectrophotometry, and the concentration (mg / L) was calculated by calculating the amount of Cd from the calibration curve prepared in advance. Perform a background test to calibrate.

hemp. Hexavalent chromium ( Cr6 +)

Hexavalent chromium is quantified according to inductively coupled plasma emission spectrophotometry. The quantitative range is 0.007-50 mg / l at 267.72 nm, depending on the equipment used and the measurement conditions. The emission intensity of the sample solution was measured at 267.72 nm according to the inductively coupled plasma emission spectrophotometry, and the concentration (mg / L) was calculated by calculating the amount of chromium from the calibration curve prepared in advance. Perform a background test to calibrate.

Figure 7a) is shown for the heavy metal dissolution test of the solid prepared by mixing 70% by weight of clay and 30% by weight of silica sand. As a result of heavy metal elution, when Styrofoam was injected by 5% to 15% by volume, As was 0.001 to 0.002ppm, which was significantly lower than the heavy metal elution standard. In addition, Cd was detected at 0.084 ppm in the original sample, but was stabilized during firing and was not detected at all in the solid material. In other Cu, Cr + 6, Pb, etc., no heavy metals were detected. Even when 5% by volume to 15% by volume of phage was injected, 0.001 to 0.002 ppm of As was significantly lower than the heavy metal elution standard, but no other heavy metals such as Pb, Cu, Cd, and Cr + 6 were detected.

Similarly, when only 5% to 15% by volume of sawdust was injected, only As was detected at 0.001 to 0.002 ppm, which is significantly lower than the heavy metal elution standard, but no other heavy metals such as Pb, Cu, Cd, and Cr + 6 were detected.

FIG. 7 b) shows the heavy metal dissolution test of the solid prepared by mixing 60 wt% clay and 30 wt% silica sand with 10 wt% sludge. In the case of injection of 10% by weight of sludge, As was 0.001 to 0.002ppm, which was significantly lower than the heavy metal elution standard. In addition, Cd was detected at 0.084 ppm in the original sample, but was stabilized during firing and was not detected at all in the solid material. Other heavy metals such as Pb, Cu, Cr + 6 were not detected at all and showed a similar tendency to that when no sludge was injected.

Even when 5% to 15% by volume of styrofoam and phage were injected, As was found to be 0.001 to 0.002 ppm, which is significantly lower than the heavy metal elution standard, but no other heavy metals such as Pb, Cu, Cd, and Cr + 6 were detected.

Similarly, when only 5% to 15% by volume of sawdust was injected, only As was detected at 0.001 to 0.002 ppm, which is significantly lower than the heavy metal elution standard, but no other heavy metals such as Pb, Cu, Cd, and Cr + 6 were detected.

FIG. 8a) shows the heavy metal dissolution test of the solid prepared by mixing 50% by weight of clay and 30% by weight of silica sand with 20% by weight of sludge. In the case of injection of 20% by weight of sludge, As was 0.001 to 0.002ppm, which was significantly lower than the heavy metal elution standard. In addition, Cd was detected at 0.084 ppm in the original sample, but was stabilized during firing and was not detected at all in the solid material. Other Cu, Cr + 6, Pb, etc. showed no tendency to detect heavy metals and showed a similar tendency as when sludge was injected by 10% by weight.

Even when 5% to 15% by volume of styrofoam and phage were injected, As was found to be 0.001 to 0.002 ppm, which is significantly lower than the heavy metal elution standard, but no other heavy metals such as Pb, Cu, Cd, and Cr + 6 were detected. Similarly, when only 5% by volume to 15% by volume of sawdust was injected, only As was detected at 0.001 to 0.002 ppm, which is significantly lower than the heavy metal elution standard, but no other heavy metals such as Pb, Cu, Cd, and Cr + 6 were detected.

FIG. 8 b) shows a heavy metal elution experiment of a solid prepared by mixing 30 wt% clay and 30 wt% silica sand with 40 wt% sludge. Even when 40% by weight of sludge was injected, As was 0.001 to 0.002ppm, which was significantly lower than the heavy metal elution standard. In addition, Cd was detected at 0.084 ppm in the original sample, but was stabilized during firing and was not detected at all in the solid material. Other Pb, Cu, Cr + 6, etc. showed no tendency to detect heavy metals and showed a similar tendency as when the sludge was injected by 10 to 20% by weight. Even when 5% to 15% by volume of styrofoam and phage were injected, As was found to be 0.001 to 0.002 ppm, which is significantly lower than the heavy metal elution standard, but no other heavy metals such as Pb, Cu, Cd, and Cr + 6 were detected.

Similarly, when only 5% to 15% by volume of sawdust was injected, only As was detected at 0.001 to 0.002 ppm, which is significantly lower than the heavy metal elution standard, but no other heavy metals such as Pb, Cu, Cd, and Cr + 6 were detected.

According to the light brick manufacturing method (1) using the sludge of the present invention as described above, as a result of studying whether the sludge (Sludge) can be mixed with the general clay can be used as an auxiliary material instead of clay in the production factory of the light brick (55), If no pore is added, even if the sludge is injected in an amount of 10% to 20% by weight, the clay brick quality standards satisfy 1 to 3 types. In addition, even if injecting 10% by weight of sludge into 5% by volume of styrofoam or 5% by weight of sawdust as a lightweighting agent, it satisfies the quality standard of compressive strength.

In addition, even when injecting about 10% by weight of sludge instead of clay in the manufacture of clay bricks satisfies the quality standards, if used as an auxiliary material can reduce the manufacturing cost.

In addition, heavy metal dissolution test is stabilized in the process of plasticizing lightweight bricks (55) appearing less than the detection limit or no detection in the original sample, harmless and there is little risk for heavy metals.

At present, the treatment of purified water sludge is mainly filled with landfill material, road substrate material, and cover material, which may affect natural ecosystems such as groundwater due to leachate accumulated by secondary environmental pollution. It can be used as a feedstock instead of clay.

According to the present invention as described above, by producing lightweight bricks using sewage sludge and wastewater sludge, not only can waste be effectively recycled, but also stabilization and harmlessness can be minimized instead of landfill, thereby minimizing environmental pollution. have.

In addition, according to the present invention, it is possible to produce high-quality lightweight bricks at low cost using sludge waste, thereby obtaining an excellent effect that enables various utilization of resources.

Although the present invention has been described in detail with reference to the accompanying drawings, the present invention is not limited to such a specific structure. Those skilled in the art will be able to variously modify or change the embodiments of the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. Nevertheless, it will be apparent that all such modifications or design modifications to such simple embodiments will clearly fall within the scope of the present invention.

1 is a process flowchart showing a step-by-step process for producing lightweight brick using sludge according to the present invention;

2 is a block diagram of a drying furnace used in the experimental example of the method for producing a light brick using sludge according to the present invention;

3 is a photograph showing a series of experimental examples of the method for manufacturing a light brick using sludge according to the present invention,

a) a picture of mesh 18 sifting the raw material,

b) a photo of mixing the pore agent with the turning raw material,

c) photos of forming bricks in turning molding machine,

d) pictures of bricks of actual size,

e) pictures of the kiln;

4 is a graph showing the change in compressive strength according to the change amount of clay, purified water sludge, and pore injection obtained in a series of experimental examples of the method for producing light brick using sludge according to the present invention;

5 is a graph showing the absorption rate change according to the clay, purified water sludge, pore injection amount obtained in the present invention;

Figure 6 is a chart showing the light weight rate characteristics of the clay, purified water sludge, the pore-agent injection amount obtained in the present invention;

7 is a diagram showing the elution characteristics according to the changes in the amount of clay, silica sand, pore injection obtained in the present invention, a) is a characteristic diagram of 70% by weight of clay, b) is a characteristic diagram of 60% by weight of clay;

8 is a diagram showing the elution characteristics according to the change amount of the clay, silica sand, pore injection obtained in the present invention, a) is a characteristic diagram of 50% by weight of clay, b) is a characteristic diagram of 30% by weight of clay.

<Description of Symbols for Major Parts of Drawings>

1 ...... Lightweight Brick Manufacturing Method Using Sludge According to the Present Invention

10 ..... drying the raw material consisting of sludge, clay and silica sand

20 ..... Step to shred the raw material

30 ..... Mixing raw materials consisting of sludge, clay and silica sand

40 ..... Steps to Form Brick

50 ..... Low temperature drying of bricks

60 ..... Steps to produce brick by firing and cooling to high temperature

12 ..... Dryer 15 ..... Mesh No. 18

22 ..... Porosity 25 ..... Raw Material

32 ..... molding machine 34 ..... compression molding machine

55 ..... Lightweight Brick 62 .....

Claims (10)

In the method of producing lightweight brick using sludge, Drying the raw material consisting of sludge, clay and silica sand; Crushing the raw material; Mixing the raw material consisting of sludge, clay and silica sand; Forming bricks; Low temperature drying of the bricks; And The method of manufacturing a light weight brick using sludge, comprising the steps of: firing and cooling the brick to a high temperature to produce it. The method of claim 1, wherein the step of drying the raw material is a low-temperature drying of the purified sludge at 40 ℃ ~ 50 ℃, the sewage sludge is characterized in that the sludge is removed by the high temperature drying at 800 ℃ ~ 1000 ℃ sludge Light brick manufacturing method using. The method of claim 1, wherein the mixing of the raw materials comprises supplying 17 wt% to 25 wt% of water to the sludge 10 wt% to 40 wt%, clay 30 wt% to 70 wt%, and silica sand 30 wt%. Light brick manufacturing method using the sludge, characterized in that. 4. The method of claim 3, wherein the mixing of the raw materials is performed by further mixing any one of styrofoam, phage or sawdust as a pore material. The method of claim 3, wherein the step of mixing the raw materials is supplied with 17% by weight of water to the raw material of 10% by weight of sludge, 60% by weight of clay, 30% by weight of silica sand, 5 to 15% by volume relative to the raw material as a pore material Light brick manufacturing method using the sludge, characterized in that the mixture is made of styrofoam in proportion. 6. The method of claim 5, wherein the mixing of the raw materials comprises mixing styrofoam at a rate of 5% by volume with respect to the raw materials as the pore material. [6] The method of claim 5, wherein the mixing of the raw materials comprises using sawdust as a pore material and mixing at a rate of 5% by volume with respect to the raw materials. The method of claim 1, wherein the step of drying the bricks at low temperature is performed at room temperature at 20 ° C to 40 ° C and then completely dried in a dryer at 60 ° C to 70 ° C for 48 hours. The method of claim 1, wherein the sintering step of the brick is heated to 500 ℃ in a kiln to maintain for 2 hours, the first firing, heating from 500 ℃ to 800 ℃ maintained for 2 hours to secondary firing, 800 ℃ Method of manufacturing a light-weight brick using sludge, characterized in that the heating to 1100 ℃ for 2 hours to maintain the third firing, and then cooled in a kiln. 10. The method of claim 9, wherein the step of firing the bricks is allowed to cool from 1100 ° C to 300 ° C, and at 300 ° C, the door of the kiln is opened by 20%, and at 200 ° C, the door of the kiln is opened by 40%. Light brick manufacturing method using the sludge, characterized in that the open enough to supply air.

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