阅读说明：本技术 一种污泥降粘处理制备污泥水煤浆的方法 (Method for preparing sludge coal water slurry through sludge viscosity reduction treatment ) 是由 王燕芳 李发林 崔豫泓 王国房 *** 蔡洪涛 何红兴 苏鑫 张静 张桂玲 杜丽 于 2019-10-08 设计创作，主要内容包括：本发明公开了一种污泥降粘处理制备污泥水煤浆的方法。所述方法包括如下步骤：污泥经降粘处理得到降粘污泥；所述降粘污泥与煤粉、分散剂和制浆用水混合,经搅拌和剪切即得到污泥水煤浆；所述煤粉由原料煤经粉碎得到；所述降粘处理包括如下步骤：所述污泥与污泥降粘剂和所述制浆用水的混合液在转速为1000～10000转的污泥处理器中进行处理。本发明方法中,污泥添加量较多、添加剂添加量少,所制备得到的水煤浆具有浓度较高、粘度低、流动性好,适合于燃烧或作为气化原料。本发明解决了污泥直接与煤制备水煤浆时添加量少或者水煤浆浓度过低的问题。(The invention discloses a method for preparing sludge coal water slurry through sludge viscosity reduction treatment. The method comprises the following steps: viscosity reduction treatment is carried out on the sludge to obtain viscosity reduction sludge; mixing the viscosity-reducing sludge with coal dust, a dispersing agent and water for pulping, and stirring and shearing to obtain sludge coal water slurry; the coal powder is obtained by crushing raw material coal; the viscosity reduction treatment comprises the following steps: and treating the mixed liquid of the sludge, the sludge viscosity reducer and the pulping water in a sludge treater at the rotating speed of 1000-10000 r. In the method, the sludge addition amount is large, the additive addition amount is small, and the prepared coal water slurry has high concentration, low viscosity and good fluidity and is suitable for combustion or used as a gasification raw material. The invention solves the problems of little addition amount or low concentration of the coal water slurry when the sludge is directly mixed with coal to prepare the coal water slurry.)

1. A method for preparing sludge coal water slurry by reducing viscosity of sludge comprises the following steps:

viscosity reduction treatment is carried out on the sludge to obtain viscosity reduction sludge; mixing the viscosity-reducing sludge with coal dust, a dispersing agent and water for pulping, and stirring and shearing to obtain sludge coal water slurry;

the pulverized coal is obtained by crushing raw material coal.

2. The method of claim 1, wherein: the viscosity reduction treatment comprises the following steps:

and treating the mixed liquid of the sludge, the sludge viscosity reducer and the pulping water in a sludge treater at the rotating speed of 1000-10000 r.

3. The method of claim 2, wherein: the sludge viscosity reducer is at least one of sodium hydroxide, potassium hydroxide, calcium oxide, calcium chloride, magnesium chloride, ferric chloride, potassium permanganate and potassium ferrate;

the mass ratio of the sludge to the sludge viscosity reducer is 10: 0.1 to 1.

4. The method according to any one of claims 1-3, wherein: the coal powder is a mixture of coarse powder and superfine powder;

the particle size of the coarse powder is more than 100-600 mu m;

the particle size of the superfine powder is less than or equal to 50 mu m.

5. The method of claim 4, wherein: the superfine powder is obtained by grinding fine powder;

the granularity of the fine powder is less than 100-600 mu m;

the coarse powder and the fine powder are obtained by screening particles obtained by crushing the raw material coal;

the mass ratio of the coarse powder to the fine powder is 1.5-10: 1.

6. the method according to any one of claims 1-5, wherein: the raw material coal is anthracite or bituminous coal.

7. The method according to any one of claims 2-6, wherein: the mass ratio of the coal powder to the viscosity-reducing sludge is 100: 10 to 30.

8. The method according to any one of claims 1-7, wherein: the dispersant is at least one of naphthalene sulfonate, lignosulfonate and humate;

the addition amount of the dispersing agent is 0.1-2.0% of the mass of dry coal in the pulverized coal.

9. The method according to any one of claims 2-8, wherein: the pulping water is water, papermaking black liquor and/or printing and dyeing wastewater;

in the step of viscosity reduction treatment and the step of sludge water-coal slurry preparation, the mass ratio of the addition amount of the pulping water to the raw material coal is (15-30): 100.

10. sludge coal water slurry obtainable by the process according to any one of claims 1 to 9.

Technical Field

The invention relates to a method for preparing sludge coal water slurry by viscosity reduction treatment of sludge, belonging to the technical field of sludge resource utilization.

Background

Along with the increase of urban population in China, the treatment capacity of municipal sewage is increased, the product sludge of the sewage is increased year by year, at present, more than 4000 ten thousand tons of sludge are obtained every year, and the annual output of the municipal sludge in China is estimated to reach 6000 to 9000 ten thousand tons in 2020. The sludge contains a large amount of toxic and harmful substances including heavy metals, persistent organic pollutants, parasitic ova, pathogenic microorganisms and the like, and if the sludge cannot be properly treated, the sludge is bound to be a timing bomb for detonating an environmental crisis. Therefore, the problem to be solved is to properly dispose the sludge and utilize the sludge as resources. At present, over 3000 million tons of sludge which is not properly treated every year in China accounts for over 75 percent of the sludge yield. The domestic sludge treatment method mainly adopts landfill, not only occupies land and causes secondary pollution, but also has high disposal cost. The incineration decrement is obvious, and is one of the international sludge treatment directions. However, the sludge has high water content of about 80 percent and low self heat value of about 6-10 MJ/kg, and can not be directly combusted usually. The sludge and the coal are mixed and incinerated cooperatively, so that the investment and the treatment cost of sludge treatment are effectively reduced, and the method is one of sludge treatment directions supported by the nation.

The coal water slurry is a clean and efficient coal-based fluid fuel and gasification raw material consisting of coal, water and additives, is developed in the oil crisis in the 70 th 20 th century, and has the characteristics of good fluidity, high combustion efficiency, energy conservation, environmental protection and the like. By the end of 2017, the design capacity of the national fuel coal water slurry has broken through 5000 ten thousand tons/year, the production and usage amount has reached 3000 ten thousand tons/year, and the national fuel coal water slurry is mainly applied to oil and coal substitution combustion of power station boilers, industrial boilers and kilns; in the field of coal water slurry gasification, the large entrained flow gasification technology used as coal water slurry feeding becomes the mainstream coal gasification technology in China due to the advantages of low investment and high maturity. At present, many coal chemical engineering projects such as synthetic ammonia, coal-made methanol, coal-made dimethyl ether, coal-made olefin, coal-made oil, coal-made natural gas and the like which are put into production and under construction in China mostly adopt a coal water slurry pressure gasification technology. The production quantity of the gasification furnaces containing a plurality of nozzles, GE, multi-component slurry and the like fed by the coal water slurry is nearly 300 sets, the annual slurry consumption is 1.2 hundred million tons, and the coal consumption for the gasification of the coal water slurry in the future is 2 hundred million tons.

The sludge coal water slurry is prepared by mixing the sludge and coal by utilizing the heat value and water contained in the sludge and is used as boiler fuel or gasification raw material, so that the sludge is reduced and harmless, the heat value and water in the sludge are fully utilized, coal and water resources for pulping are saved, and the method is a good method for recycling the sludge.

Therefore, related experts in China have studied on the preparation of the coal water slurry by using the sludge in recent years, but the sludge has the characteristics of high viscosity, high water retention and no flow, so that the preparation of the coal water slurry by directly mixing the sludge with the coal has the problems of small addition amount of the sludge, difficulty in mixing with the coal, high pulping cost, poor quality of the coal water slurry and difficulty in large-scale application.

Disclosure of Invention

The invention aims to provide a method for preparing sludge coal water slurry by viscosity reduction of sludge, namely a method for preparing coal water slurry by mixing sludge and coal after viscosity reduction treatment.

The method for preparing sludge water-coal-slurry by reducing viscosity of sludge provided by the invention comprises the following steps:

viscosity reduction treatment is carried out on the sludge to obtain viscosity reduction sludge; mixing the viscosity-reducing sludge with coal dust, a dispersing agent and water for pulping, and stirring and shearing to obtain sludge coal water slurry;

the coal dust is obtained by crushing and grinding raw material coal.

In the method, the viscosity reduction treatment comprises the following steps:

treating the mixed liquid of the sludge, the sludge viscosity reducer and the pulping water in a sludge treater with the rotation speed of 1000-10000 r;

the sludge treater may be a high efficiency grinding disperser.

Specifically, the sludge viscosity reducer can be at least one of sodium hydroxide, potassium hydroxide, calcium oxide, calcium chloride, magnesium chloride, ferric chloride, potassium permanganate and potassium ferrate;

the sludge viscosity reducer can be a mixture of sodium oxide, potassium hydroxide, calcium oxide, calcium chloride, magnesium chloride, ferric chloride, potassium permanganate and potassium ferrate, and the mass ratio of the mixture to the mixture can be 5-40: 1-5: 1-50: 2-20: 5-30: 1-10: 1-5: 2-30, specifically 20-30: 5: 20-30: 4: 5-10: 6: 5: 20-25, 20: 5: 30: 4: 5: 6: 5: 25 or 30: 5: 20: 4: 10: 6: 5: 20.

in the method, the mass ratio of the sludge to the sludge viscosity reducer can be 10: 0.1 to 1, specifically 10: 0.3-0.5, 10: 0.3 or 10: 0.5.

in the method, the coal powder can be a mixture of coarse powder and superfine powder;

the particle size of the coarse powder is more than 100-600 mu m;

the particle size of the superfine powder is less than or equal to 50 mu m.

Wherein the ultrafine powder is obtained by grinding fine powder;

the granularity of the fine powder is less than 100-600 mu m;

the coarse powder and the fine powder are obtained by screening particles (the particle size is less than 1-3 mm) obtained by crushing the raw material coal;

the mass ratio of the coarse powder to the fine powder can be 1.5-10: 1, specifically 4 to 5.7: 1. 4: 1 or 5.7: 1.

in the method of the invention, the raw material coal is anthracite or bituminous coal.

In the method, the mass ratio of the pulverized coal to the viscosity-reducing sludge can be 100: 10-30, preferably 100: 15-20, 100: 15 or 100: 20.

in the method of the invention, the dispersant can be at least one of naphthalene sulfonate, lignosulfonate and humate;

the addition amount of the dispersing agent can be 0.1-2.0% of the mass of dry coal in the pulverized coal, preferably 0.4-0.5%, 0.4% or 0.5%.

In the method, the water for pulping can be water, papermaking black liquor and/or printing and dyeing wastewater.

In the method, in the step of viscosity reduction treatment and the step of sludge water-coal slurry preparation, the mass ratio of the addition amount of the pulping water to the raw material coal is 15-30: 100, such as 20: 100 or 25: 100, the amount of water in the two steps can be appropriately adjusted within the above range.

The concentration of the sludge water-coal slurry prepared by the method can reach more than 60 percent, and the sludge water-coal slurry can be used as boiler fuel and gasification raw materials.

The invention adopts various chemical raw materials as the sludge viscosity reducer and combines a special sludge processor to pretreat the sludge, and then the treated sludge is mixed with coal and a dispersant to prepare the sludge water-coal-slurry for boiler combustion and gasification of a gasification furnace. Compared with the direct sludge pulping, the molecular chain of the macromolecular compound playing a role of flocculation in the sludge is broken into micromolecules or depolymerized to release partial free water after the sludge is subjected to high-speed shearing, crushing, fine grinding and the like for tens of millions of times per minute under the combined action of the viscosity reducer and the special processor; meanwhile, inorganic substances in the sludge are ultrafine crushed into nano particles which are uniformly dispersed in the treated sludge mixed liquid, and finally the sludge is changed into fluid with very good fluidity from large agglomerates containing particles with different sizes, so that when the sludge and coal are mixed for pulping, the proportion of the sludge is improved or the concentration of the prepared water-coal-slurry is also greatly improved, wherein the pulping concentration of low-rank coal can reach more than 60 percent. The invention solves the problems of little addition amount or low concentration of the coal water slurry when the sludge is directly mixed with coal to prepare the coal water slurry.

Detailed Description

The experimental procedures used in the following examples are all conventional procedures unless otherwise specified.

Materials, reagents and the like used in the following examples are commercially available unless otherwise specified.