Sulfur-fixing coal-saving additive
The present invention relates to treating solid fuels to enhance their combustion, reducing smoke in the form of additives, promoting smoke removal, and minimizing corrosion encrustation, and particularly to sulfur-fixing, coal-saving additives.
In the background art, the energy of China is mainly coal, and the coal accounts for 74% of the primary energy, most of the coal of China is formed by alternate deposition of sea and land, the sulfur content is generally high, and after combustion, main pollutants discharged to the atmospheric environment are as follows: sulfur dioxide, soot particulates, nitrogen oxides, and carbon monoxide. Statistically, 96% of the pollutants emitted by fuel combustion are derived from coal combustion, and about 90% of the SO2About 96 percent of smoke dust comes from coal combustion directly, so that the smoke dust type pollution prevention is the most urgent task for protecting the atmospheric environment, and the important prevention and treatment is the sulfur dioxide and smoke dust particles in the atmosphere. Atmospheric coal pollution at home and abroadThe main treatment methods include ① pretreatment, in which a coal washing plant is established to wash most of sulfur and sulfide with water before coal combustion, ② treatment in the combustion process, CaO is added into a combustion chamber to react with SO2Reaction to produce CaSO3And CaSO4. Due to the formation of CaSO4The optimum temperature is below 800 ℃, SO that the low-temperature staged combustion technology is required, typical equipment comprises a circulating fluidized bed and a furnace calcium injection device, the technology is not suitable for the reconstruction of the existing equipment, ③ post-treatment, the coal combustion generates a large amount of SO2Then, proper chemical and physical measures are adopted for desulfurization and dust removal in the process of flue gas emission, and the flue gas desulfurization method is mainly adopted in developed countries, so that the technical process is complex, the equipment is huge, the investment is high, and the equipment running cost is high. The above methods require a large equipment investment and a high equipmentrunning cost, and require a certain period of boiler modification. The Chinese patent publication of invention, No. 3/24 1993, discloses a method for making briquettes, which is disclosed in CN 1070219A. The method is that the combustion improver is added into the raw materials of coal powder, adhesive and water, and the components of the combustion improver areThe weight ratio of the catalyst sodium nitrate is 30-38%, the oxidant potassium permanganate is 0.3-1%, the sulfur fixing agent sodium carbonate is 2-4%, and the balance is the scarification agent sodium oxide. And (3) completely dissolving a combustion improver accounting for 1.5-4 per mill of the mass of the coal powder in water, mixing the mixture into the coal powder, stirring the mixture uniformly, adding a binder and the water, stirring the mixture uniformly, and finally, pressurizing and molding the mixture in a mold. The product has simple formula, few components and single function of each component, the action of each substance in the components of the formula is superposed, the overall efficiency is low, when the addition amount is 2 per mill, the coal saving rate is only 5-8%, the additive has the combustion-supporting and coal saving effects, but the sulfur-fixing and environmental-protection effects are low, the additive is widely applied to inferior coal and used on a chain furnace, the application range of the additive is limited, the coking phenomenon in use is difficult to effectively overcome, the heat loss of the boiler is increased along with the increase of the heat loss of the boiler, the number of times of cleaning the boiler is increased, and the normal operation of the boiler is influenced.
Aiming at the problems of the coal additives in the background technology, the applicant researches seriously, accumulates and develops, refers to a large amount of data and documents, and after 30 times of experiments, investsmore than 80 ten thousand yuan, consumes more than two years, and develops and researches the XAIA series sulfur-fixing and coal-saving additives with unique advantages according to the characteristic that environmental problems are more and more emphasized by people, so that the aims of stabilizing the functions of components, scientifically and reasonably preparing a formula, improving the combustion efficiency of coal, improving the heat conduction efficiency of a boiler, saving coal and fixing sulfur and effectively treating atmospheric pollution are fulfilled.
The technical solution of the invention is as follows:
the components of the composition are as follows: the sulfur-fixing agent is light calcium carbonate CaCO3CaO, and the oxidizing agent is potassium permanganate KMnO4Sodium nitrate NaNO3The leavening agent is sodium chloride NaCl, and the stabilizing agent is silicon dioxide SiO2Strontium oxide SrO, the catalyst is ferric oxide FeO3The adjuvant is sodium carbonate Na2CO3。
The technical solution of the present invention further comprises:
taking CaCO as sulfur-fixing agent in the components318-22% of an oxidant KMnO42~4%、NaNO312-18%, a swelling agent NaCl 41-46%, and a stabilizing agent SiO2Or SrO or borax Na2B4O70.5-2% of Fe as catalyst2O31-2% of auxiliary agent Na2CO313-18% of sulfur-fixing coal-saving comprehensive additive.
Taking CaCO as sulfur-fixing agent in the components323-28%, CaO 25-30%, and an oxidant KMnO42.3~3%、NaNO38-12%, leavening agent NaCl 20-25%, stabilizing agent SiO2Or SrO or borax Na2B4O71-2% of catalystFe2O31-3% of auxiliary agent Na2CO38-12% of sulfur-fixing reinforced additive.
Taking CaCO as sulfur-fixing agent in the components338-42%, CaO 30-35%, and an oxidant KMnO42.3~3%、NaNO35-6%, leavening agent NaCl 5-15%, stabilizing agent SiO2Or SrO 2-4%, catalyst Fe2O31-2% of auxiliary agent Na2CO35-7% of sulfur-fixing additive.
Taking CaCO as sulfur-fixing agent in the components30% of an oxidizing agent KMnO43~4%、NaNO325-30%, leavening agent NaCl 55-60%, catalyst Fe2O31-2% of auxiliary agent Na2CO37-12% to form the coal-saving additive.
Taking CaCO as sulfur-fixing agent in the components318-23% of an oxidant KMnO41~2%、NaNO340-45%, leavening agent NaCl 25-30%, stabilizing agent SiO21-3% of catalyst Fe2O32-3 percent of silicon carbide SiC is additionally added43-5% to form the coal-saving reinforced additive.
The technical solution of the present invention further comprises:
the process method of the sulfur-fixing coal-saving additive comprises the following steps:
① inspecting and feeding raw materials, wherein the raw materials are mixed according to the composition and meet the corresponding requirements of GB, HB or QB;
② crushing, namely crushing the coarse or agglomerated raw materials by a crusher to obtain the fineness of 100-200 meshes;
③ stirring, wherein the raw materials in the formula are added into a stirrer by belt conveying, the materials are slowly and uniformly fed, and the temperature of the stirred materials is required to be lower than 150 ℃;
④ inspecting, wherein the qualified product is free of impurities, uniform in color and fineness, and light red brown or dark red brown in surface;
⑤ bagging and weighing, namely bagging after the product is qualified by inspection, wherein the large bag is packed by 25 kg per bag, and the small bag is packed by 1 kg per bag;
⑥ hot-pressing and sealing, namely, sticking the laser anti-counterfeiting mark on the bag after the quality certificate and the use instruction are put into the bag, and hot-pressing and sealing the bag;
⑦ packaging and sewing, namely packaging and sewing the outer packaging bag by a plastic woven bag by a hand-held sealing machine;
⑧ filling in type and batch number, and storing.
The embodiment of the invention is as follows:
the formula comprises the following components:
coal-saving reinforced additive of sulfur-fixing additive
Feedstock I II III I II III I II III I II III I II III
CaCO3 18 20 22 23 26 28 42 38 39 18 20 23
CaO 30 25 8 35 30 32
KMnO4 4 2 3 3 2.6 2.3 2.3 2.8 3 3 4 3.5 1 1.5 2
NaNO3 16 18 12 10 12 8 6 5.5 5 29.5 28 25 45 43 40
NaCl 46 41.5 42.5 24 22.4 20.2 4.7 15.2 8 58 59.5 57.5 29 27 25
SiO2 2 1 0.5 2 1 1.5 3 2 4 1 2 3
Or SrO
Or Na2B4O7
Fe2O3 1 1.5 2 1 3 2 1 1.5 2 1 1.5 2 3 2.5 2
Na2CO3 13 16 18 12 8 10 6 5 7 10.5 7 12
SiC4 3 4 5
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The five components are mixed according to the composition, and a SJ-03 type salt pulverizer is used for pulverizing coarse or caked raw materials, and the required fineness is 100-200 meshes. Conveying the raw materials into a stirrer through a belt, slowly and uniformly feeding the raw materials, starting stirring when the raw materials are added to one half of a charging barrel, stopping feeding when the raw materials are added to two thirds of the charging barrel, stirring for about 10 minutes, and stopping the machine for inspection. And (3) inspecting the product to be free of impurities, uniform in color and fineness, and light reddish brown or dark reddish brown on the surface, and after the product is qualified, bagging and weighing, wherein the weight of each large bag is 25 kg, and the weight of each small bag is 1 kg. Putting the qualification certificate and the use instruction in each bag, sticking the laser anti-counterfeiting mark, and sealing by hot pressing. The outer packing bag is packed and sewed by a plastic woven bag by a hand-held sealing machine. Filling in the model and batch number, and warehousing for storage.
The invention is used in such a way that additives with different components and different types can be selected according to the respective requirements of users, 2 per mill of sulfur-fixing coal-saving additive is added into raw coal for combustion, and the raw coal is uniformly scattered into the raw coal for combustion and then enters a furnace for combustion, thereby saving coal and reducing the emission of SO2 in combustion flue gas. Or adding 2 per mill of coal-fixing and throttling additive into raw coal uniformly (removing sulfur-fixing additive component), adding proper amount of adhesive and water, and press-forming in forming mould to obtain the finished product of briquette.
The invention has the following advantages and effects:
1. coal saving: under the premise that the evaporation capacity of the boiler is certain, the coal consumption is mainly determined by the combustion efficiency of coal and the heat transfer efficiency of the boiler body, and the following two aspects are explained:
① the combustion efficiency of coal is improved by secondary micro-explosion, because the coal is massive and piled in the coal layer, the coal is hard to contact with the oxygen in the air and can not be burned effectively, the carbon content of the slag is high, the leavening agent crystal of the invention will burst in the coal layer under the high temperature of the hearth, so the coal lump with larger particles is broken, the gas in the coal layer and the coal layer is stirred, the coal layer puffs to improve the air permeability of the coal layer, the combustible components of the coal are burned sufficiently with the oxygen, the burning intensity is improved, thereby the burning efficiency of the coal is improved.
② inhibits and eliminates coking, improves heat conduction efficiency of boiler, the soot and ash generated by burning raw coal in boiler are adhered on inner wall of boiler furnace, boiler water pipe, flue gas channel and dust removing equipment, after long time, the wall thickness of equipment is reduced due to corrosion, the ash scale on inner wall of boiler furnace is thickened to reduce air ventilation section, increase resistance, change combustion volume ratio, and the wall thickness of boiler furnace ash scale is increased by more than 5% when heat efficiency is reduced, exhaust gas temperature is raised, energy consumption is raised, practice proves that the wall thickness of boiler furnace ash scale is increased by 1 mm, the invention adopts leavening agent, stabilizer and expanded sand Na2B4O7A small amount of metallic zinc powder (Zn) to form a loose dust-cleaning antiscale agent, and CaSO as the main component of the dust4、Al2(SO4)3、MgSO4、K2SO4The chloride is generated by reaction, the melting point is low, and the chloride is volatile at 772-801 ℃, and enters the inner wall of the hearth, the wall of the flue and the wall of the dust removal equipment together with the flue gas, so that the deposited dust becomes porous and loose, and then is pulverized and dropped, and the effects of removing the dust and the scale, inhibiting coking and removing coke are achieved. After the expanded sand is heated, strong alkaline sodium metaborate (Na) is decomposed2BO2) The melting point of the ash scale is reduced, so that the ash scale removing reaction can be carried out in a liquid phase, and good favorable conditions are created. The stabilizer has the function of inhibiting high-temperature corrosion, and prolongs and protects the service life of boiler walls, flue walls and dust removal equipment.The metal zinc is added to protect the metal and inhibit corrosion. Thus, through decoking and descaling, the heat conductivity coefficient of the water pipe wall is increased, the heat conduction of the pipe wall is improved, the heat loss is reduced, the heat efficiency is improved, and according to tests, the output of the boiler is improved, and the coal saving rate can reach more than 10 percent and can reach 25 percent at most. This is a second feature of the present invention.
2. And (3) sulfur fixation: the sulfur in coal can be divided into inorganic sulfur and organic sulfur, and the inorganic sulfur is FeS
2、MgSO
4S, in which FeS is used
2At most, the sulfur is of the general formula R-S, the sulfur is combustible, most of the sulfur is generated by burning SO at about 400 DEG C
2And sulfur fixation is SO
2Is fixed in the slag in the form of sulfate SO as to lead SO in the flue gas
2The content is reduced. In general, sulfur in the sulfate is difficult to decompose and is incombustible sulfur, which enters ash, and in practice, the sulfate of some metals at high temperature can decompose:
in reality, the coal combustion temperature of most of combustion furnaces such as boilers, kilns and stoves generally does not exceed 1100 ℃. The invention adopts sulfur-fixing agent light calcium carbonate and catalyst to realize sulfur fixation, and the reaction formula is as follows:
wherein the catalyst is Fe
2O
3The sulfur fixation reaction speed of the two formulas is improved and accelerated, thereby achieving the purpose of improving the sulfur fixation rate. The combustion sulfur fixation rate is mainly determined by the stage that the temperature is lower than 500 ℃. The invention adopts the sulfur-fixing agent, the catalyst, the oxidant and the stabilizer, not only can ensure the coal to be fully combusted, but also can ensure SO generated by the combustion of the coal
2、SO
3When the sulfate is changed into salt, the salt is fixed in the slag, in which the stabilizing agent can make the sulfate not be decomposed, and can not be discharged with flue gas, and finally can implement the actions of fixing sulfur, supporting combustion, removing smoke and removing dust, so that it is the third action of said inventionIs characterized in that.
3. And (3) high-temperature sulfur fixation: because the sulfur fixing agent is adopted, calcium sulfate is generated by combustion, sulfur is fixed in slag, but the calcium sulfate is decomposed after the furnace temperature reaches 1200-1450 ℃, SO that SO is caused2The sulfur is escaped again to influence the sulfur fixing effect, CaCO is adopted in the invention3,Fe2O3,SiO2The SrO component and the mixed coal are burnt at the high temperature of 1500-2000 ℃ to obtain an ash residue sample, the obtained ash residue sample is subjected to X-ray fluorescence spectrum (XRFA) analysis, and the crystal in the additive is closely symbiotic to form a new stable macromolecular system according to the X-ray structural analysis result and the observation result of a scanning electron microscope: Ca-Fe-S-SiO system, the components of the additive do not participate in any chemical reaction, but play a role in preventing CaSO4The decomposition effect ensures that a large amount of sulfur can be stably reserved, the sulfur fixation efficiency of the invention is greatly improved, and the sulfur fixation technology is developed from the application of common boilers and furnaces to the application direction of large-scale industrial high-temperature boilers and furnaces, whichis the fourth characteristic of the invention.
4. The invention has scientific and reasonable formula, clear and stable functions of each component, high overall efficiency, no caking of the product and convenient use, and each component forms a series of products according to different purposes, so that various agents have respective side effects, are mutually promoted and act together to achieve the effects of sulfur fixation, coal saving, combustion supporting, smoke abatement, ash removal, descaling and corrosion prevention, and effectively increase the use range.
5. The test shows that: the temperature of the flame center of the hearth is increased by more than 100 ℃, and the combustion of the boilerThe efficiency is improved by more than 10 percent; the output of the boiler is improved by more than 10 percent; the carbon content of the slag is reduced by more than 10 percent; the blackness of the discharged smoke is obviously reduced, and the grade of 0.5-2 Ringelman can be reduced; reduction of SO2The discharge amount is 15-60%; the coal saving rate is 10-25%.
In the development of the invention, the national environmental protection agency, encyclopedia [ 1994]171, lists the invention as the 1994 best practical technical popularization project for environmental protection.