CN109369286B - Method for producing medium trace element acid soil conditioner by using fly ash and product - Google Patents
Method for producing medium trace element acid soil conditioner by using fly ash and product Download PDFInfo
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- CN109369286B CN109369286B CN201811083790.9A CN201811083790A CN109369286B CN 109369286 B CN109369286 B CN 109369286B CN 201811083790 A CN201811083790 A CN 201811083790A CN 109369286 B CN109369286 B CN 109369286B
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- C—CHEMISTRY; METALLURGY
- C05—FERTILISERS; MANUFACTURE THEREOF
- C05G—MIXTURES OF FERTILISERS COVERED INDIVIDUALLY BY DIFFERENT SUBCLASSES OF CLASS C05; MIXTURES OF ONE OR MORE FERTILISERS WITH MATERIALS NOT HAVING A SPECIFIC FERTILISING ACTIVITY, e.g. PESTICIDES, SOIL-CONDITIONERS, WETTING AGENTS; FERTILISERS CHARACTERISED BY THEIR FORM
- C05G3/00—Mixtures of one or more fertilisers with additives not having a specially fertilising activity
- C05G3/80—Soil conditioners
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F7/00—Compounds of aluminium
- C01F7/02—Aluminium oxide; Aluminium hydroxide; Aluminates
- C01F7/04—Preparation of alkali metal aluminates; Aluminium oxide or hydroxide therefrom
- C01F7/06—Preparation of alkali metal aluminates; Aluminium oxide or hydroxide therefrom by treating aluminous minerals or waste-like raw materials with alkali hydroxide, e.g. leaching of bauxite according to the Bayer process
- C01F7/0693—Preparation of alkali metal aluminates; Aluminium oxide or hydroxide therefrom by treating aluminous minerals or waste-like raw materials with alkali hydroxide, e.g. leaching of bauxite according to the Bayer process from waste-like raw materials, e.g. fly ash or Bayer calcination dust
Abstract
The invention discloses a method for producing a medium trace element acid soil conditioner by utilizing fly ash and a product. The method comprises the steps of adding nitric acid solution, sodium sulfide precipitation and the like into fly ash to remove heavy metals in the fly ash, mixing filter residues obtained after aluminum extraction and filtrate containing nitric acid obtained after heavy metal removal, and drying to obtain the medium element acidic soil conditioner which takes calcium, magnesium, silicon, potassium and nitrogen as main components and has weak alkali characteristics. According to the invention, the waste residue of the fly ash after aluminum extraction and the waste liquid from which heavy metals are removed are mixed to prepare the mineral fertilizer, so that secondary utilization of pollutants is realized, and the scientific concept of circular economic development and sustainable development is met; meanwhile, the prepared mineral fertilizer has complete nutrient elements, can achieve the effect of balanced fertilization, is used for adjusting the physicochemical property of acid soil, supplementing secondary elements in the soil, comprehensively improving the level of secondary and trace elements in the soil, obviously improving the soil environment, enhancing the biological activity, improving the nutrient form of the soil and increasing the solubility of nutrients.
Description
Technical Field
The invention relates to the technical field of resource utilization of high-alumina fly ash, in particular to a method for producing a medium-trace element acid soil conditioner by utilizing fly ash and a product.
Background
The fly ash is solid particles generated in the combustion process of a coal-fired boiler and is a byproduct of coal combustion in a thermal power plant. China is a big coal-producing country and takes coal as basic fuel for power production. The energy industry in China is steadily developed, the annual growth rate of the power generation capacity is 7.3%, the rapid development of the power industry brings about rapid increase of the emission amount of the fly ash, the total amount of the fly ash discharged by coal-fired thermal power plants is increased year by year, the emission amount of the fly ash reaches 1.25 hundred million tons in 1995, about 1.5 hundred million tons in 2000, and reaches 3 hundred million tons in 2010, and great pressure is caused to national economic construction and ecological environment in China. As a main solid waste of coal-fired power plants, fly ash has become the largest single pollution source of solid waste of china industry. The fly ash is rich in heavy metal substances such as arsenic, lead, selenium and the like and other pollutants which are harmful to human health. In China, the measures of site selection, scattering prevention, leakage prevention and loss prevention of most ash fields are far insufficient to achieve the aim of preventing the environmental pollution of the fly ash through solubility. By passing through the main coal producing area in northern China and the sand storm of a thermal power plant, a large amount of fly ash which is not subjected to anti-diffusion treatment is carried along the way and is transmitted to northern China, eastern China and even Hongkong and Australian areas, and the coal dust storm which has great threat to public health is formed.
The great harm to the production and the life of people caused by the large discharge of the fly ash is mainly shown in the following aspects: (1) land encroachment: the discharge amount of fly ash in China is increased year by year, but at present, the disposal of fly ash still takes ash stored in an ash yard as the main part, and the contradiction between fly ash storage in a pile and land occupation is more and more prominent. According to statistics, the ash piling field area is required to be 4-5 mu each ten thousand tons of fly ash is piled and stored. As far as 2002, the storage capacity of fly ash slag piles in China reaches 12.5 hundred million tons, and the fly ash slag piles occupy 5.62 ten thousand mu of total area of an ash yard, so that the non-productive land utilization causes great waste of land resources. In addition, the comprehensive treatment cost of each ton of ash is 2.40 yuan, and the cost of each ton of ash in China is up to 30-60 million yuan each year. (2) And (3) polluted soil: when the trace elements in the fly ash enter the soil and exceed the critical value, the soil can output pollutants to the environment, so that other environmental elements are polluted, the composition, structure, function and the like of the soil can be changed, and finally, soil resources can be exhausted and damaged. Research shows that the fly ash has obvious influence on the budding period and the early growth stage of corn and soybean (Yaoshitong, resource utilization of solid waste fly ash, D. doctor academic thesis, Zhejiang university: 2010), and the enrichment of elements in the root is more obvious than that in the stem. Researches indicate that the natural leachate of the fly ash has influence on growth indexes such as plant height, uniaxial weight and the like of corn and induces variation of corn genes to a certain extent. Mixing the two kinds of coarse texture soil, water-ore mud and a coal ash mixture according to the volume ratio of 3:1 and 6:1, and then carrying out chemical property analysis and pot experiment. Research results show that the content of various heavy metals in an experimental group is generally increased, except that the content of Cd is slightly overproof, the content of Cu reaches the level of poisoning the Qingjiang Chinese cabbage, other heavy metals are not overproof, pot culture experimental results show that the yield of vegetables in the experimental group is not good, and the presumed reasons are mainly that the soil air permeability and the drainage are poor due to the addition of a mixture, and the vegetables are poisoned by the heavy metal Cu. (3) And (3) polluted water body: the fly ash enters rivers and lakes along with natural precipitation surface runoff or wind to pollute ground water, and permeates into soil along with leachate to enter underground water to cause secondary pollution. The research at home and abroad finds that the coal ash leachate causes the underground water to be polluted in different degrees, obviously increases the pH value of the water body, increases toxic and harmful elements such As Cr, As and the like, and causes the coal ash to be directly discharged into the river channel and also block the river channel. In addition, the water consumption for wet ash discharge in China reaches more than 10 hundred million tons every year, and great waste of water resources is caused. (4) And (3) atmosphere pollution: because the fly ash particles are fine, the surface ash can be stripped and raised under the action of wind power when the fly ash is stacked in the open air, the ash raising height can reach 40-50 m, the visibility is influenced, and the appearance of buildings, natural landscapes and the like can be seriously damaged due to the accumulation of dust in a humid environment. (5) Harming human health: the pollution of the fly ash to water resources, soil and air directly influences the life of people, residents living in a high-dust environment for a long time have high incidence rates of nasopharyngitis, upper respiratory infection and the like, and radioactive elements in the fly ash can be accumulated in the soil, absorbed by plants and then enter human bodies through food chains.
On the other hand, China is a country with limited resource reserves occupied by everyone, the comprehensive utilization of the fly ash changes waste into valuable and harm into good, becomes an important technical and economic policy in the economic construction of China, is an important means for solving the contradiction between environmental pollution and resource shortage in power production in China, and is one of the tasks to be solved in power production.
The high-alumina fly ash is a novel aluminum resource peculiar to China, and the amount of prospect resources of the high-alumina fly ash is about 100 million tons of alumina. The bauxite resource reserves found in China are only 32 hundred million tons, the resource guarantee years are only about 20 years according to the estimation of the current mining scale, and the current external dependence of aluminum resources is as high as 55 percent. Therefore, the development and utilization of the high-alumina fly ash have practical significance for relieving the shortage of bauxite resources in China, ensuring the safety of the aluminum industry in China and enhancing the sustainable development capability of the aluminum industry.
The currently developed fly ash aluminum extraction process can be roughly divided into three major types, namely an acid method, an alkaline method and an acid-base combination method, and can produce qualified alumina products, but the problems of large emission amount of aluminum extraction residues and incapability of dissolving and dissolving the aluminum extraction residues are faced to different degrees. Taking Shenhua group 'combined impurity removal one-step acid dissolution' process for extracting aluminum oxide as an example, each 100 tons of Al is produced2O3About 130 tons of aluminum extraction residue will be discharged. The residue discharge rate of the alkaline aluminum extraction process is higher. According to the relevant regulations of aluminum industry admission conditions issued by the Ministry of industry and belief in 2013, the comprehensive utilization rate of solid wastes of a newly-built system for producing alumina by using high-alumina fly ash is required to reach more than 96%. Therefore, a high-value and high-efficiency absorption technology for the fly ash aluminum extraction residue is needed to be developed.
One of the obvious features of the residue after extracting aluminium from fly ash is rich in silicon (calcium) and poor in aluminium. At present, the utilization of the fly ash aluminum extraction residue mainly focuses on the preparation of silicon products (water glass, white carbon black, silicon micropowder and the like), the manufacture of basic building materials (cement, ceramic tiles, autoclaved bricks and the like), and the production of heat preservation, refractory materials and other fields. The application directions all have contradictions among the economic added value of products, the market capacity and the utilization rate of residues to different degrees, so that the overall utilization rate of the existing aluminum extraction residues from the fly ash is low, and the application and popularization of the high-alumina fly ash aluminum extraction technology are directly limited.
On the other hand, in 2005, the acid rain distribution area in China already occupies 28% of the total area of the national soil, while in 2010, the area is expanded to 40%, and at least more than 50% of the area of the south area in the middle and lower reaches of Yangtze river has an annual average precipitation pH value lower than 4.5, so that the area is an acid rain heavy pollution area. According to the 2010 environmental gazette in Guangdong province, the average pH value of urban rainfall is 4.86, the frequency of acid rain is 45.9%, and 5 cities belonging to a heavy acid rain area (pH <4.5) comprise Shaoshangguan, Shenzhen, Buddha, Zhaoqing, Huizhou and the like.
The pH of the soil is important for plant growth. Suitable for most crops to thrive is neutral soil, which has a pH of 7 or slightly less than 7. Soil acidification refers to a process of increasing the concentration of hydrogen ions in soil or enhancing the acidity of soil, and is characterized in that the pH value of the soil is obviously reduced, acid soil is formed, the activity of organisms in the soil is influenced, the form of nutrients in the soil is changed, the solubility of the nutrients is reduced, and free manganese ions and aluminum ions are promoted to be dissolved in a soil solution to poison crops. In nature, acid soils account for approximately 30% of the globally available soils. Under natural conditions, soil acidification is a relatively slow action process, such as carbonic acid formed by respiration of animals and plants in soil, and organic acid generated by microbial decomposition of animal and plant residues can slowly cause soil acidification. However, from the early 80 s of the last century, almost all surface soil average pH values in China have dropped by 0.13 to 0.80 unit, wherein the average pH value of red soil in southern areas has dropped by 0.23 unit but is the most acidic, and the aluminum and manganese elements are activated and harm the environment.
The acidification of the soil not only increases the acidity of the soil, but also causes the loss of a large amount of nutrient components such as potassium, calcium, silicon, magnesium and the like in the soil; the activation of aluminum, manganese and heavy metal elements is promoted, and the phenomena of aluminum toxicity and heavy metal toxicity appear; the continuous acidification of the soil also changes the population and activity of soil microorganisms; influences the root development and nutrient absorption of crops and breeds various plant diseases and insect pests.
For a long time, aiming at the common acidification of soil and adverse consequences thereof, acid soil conditioners are developed at home and abroad besides controlling atmospheric acid sedimentation and reducing the application amount of fertilizers, particularly nitrogen fertilizers. The traditional soil conditioner such as lime or limestone powder, and other soil conditioners such as caustic sludge, peat, fly ash, dolomite, phosphogypsum, ground phosphate rock, carbon-process filter mud, yellow phosphorus slag powder and the like.
After lime or limestone powder is applied to acid soil, the acidity of surface soil can be easily improved by applying the lime or limestone powder, and the concentration of exchangeable calcium ions in soil plough layer is increased. Lime is applied to red soil areas in the middle of Zhejiang, and the method comprises the following steps: the plough layer exchangeable calcium ions reach the maximum value within one and a half years after lime is applied, then slowly decline, and soil is subjected to a re-acidification phenomenon, and the mass or long-term application of lime not only causes soil hardening to form a lime hardened field, but also easily causes imbalance of elements such as calcium, potassium, magnesium and the like in the soil to cause yield reduction. Therefore, when lime is used for improving acid soil, attention must be paid that lime cannot be frequently applied, and lime is applied to improve soil simultaneously with other alkaline acid soil conditioners such as plant ash and burnt soil.
The Guangdong public agriculture science and technology company takes the caustic sludge generated in the process of producing soda by the soda industry group company Limited in southern Guangdong as a raw material to produce the acid soil conditioner with the brand of 'Master of the field', the annual output reaches 15 ten thousand tons at present, the products have 17 varieties, and the sales range is expanded from Guangdong to Guangxi, Hunan, Jiangxi, Fujian, Zhejiang, Hainan, Hubei, Shandong and the like. The main insoluble substances of the alkaline residue of the ammonia-soda process comprise calcium carbonate, calcium hydroxide, magnesium hydroxide and calcium sulfate dihydrate (gypsum), and the soluble substances comprise calcium chloride and sodium chloride, wherein the soluble substances account for 10-15%. But due to excessive chloride ions, excessive viscosity and excessive deactivated calcium carbonate (CaC 0) in the caustic sludge3More than 50 percent), the application of the acid soil conditioner is directly limited, and farmers generally reflect the phenomenon that the continuous use effect is increasingly poor.
Both peat and fly ash can be used for improving soil, increasing the content of organic matters in the soil and improving the moisture content of the soil, but the peat and the fly ash have low or neutral pH values and cannot be used for conditioning the acidity of the soil, and generally, the peat and the fly ash have low content of heavy metals and can cause secondary pollution to the soil.
Research on dolomite and the like shows that the dolomite acid soil conditioner is applied, the wheat yield is increased by 11.6-13.4%, and the rape yield is increased by 9.4-27.2%, but the soil is hardened and the crop yield is reduced due to long-term application of dolomite.
Through development, the fly ash is widely applied to various departments such as construction, building materials, water conservancy and the like. The invention aims to improve the comprehensive utilization degree of the fly ash, reduce the harm of the fly ash and improve the economic benefit. Adding nitric acid to dissolve out heavy metals, precipitating the dissolved heavy metals by using sodium sulfide to obtain filtrate containing nitrate radicals, mixing residues obtained after aluminum is extracted from fly ash and the filtrate, drying and grinding to obtain the nutritional type acid soil conditioner mainly containing silicon-calcium-magnesium-aluminum secondary elements which is urgently needed by acid soil.
Disclosure of Invention
The invention aims to provide a method and a product for producing a medium-trace element acid soil conditioner by utilizing fly ash, aiming at the defects of the prior art, and the method is a resource utilization method of high-alumina fly ash, and specifically comprises the following steps: the heavy metals in the fly ash are removed by adding nitric acid into the fly ash for dissolution and sodium sulfide precipitation, and then the filter residue after aluminum extraction and the filtrate after heavy metals removal are mixed and dried to obtain the medium element acid soil conditioner which takes calcium, magnesium, silicon, potassium and nitrogen as main components and has weak alkali characteristics. The method can remove heavy metals in the high-alumina fly ash in a soluble manner, and can carry out resource utilization on the waste residue after the heavy metals are removed to produce the medium-trace element acid soil conditioner.
The purpose of the invention is realized by the following technical scheme.
A method for producing a medium trace element acid soil conditioner by utilizing fly ash comprises the following steps:
(1) heavy metal dissolution: mixing the fly ash and nitric acid, performing ultrasonic treatment and shaking table vibration to disperse the mixture uniformly, standing the mixture, and performing vacuum filtration;
(2) heavy metal precipitation removal: adding a sodium sulfide solution into the filtrate obtained after suction filtration in the step (1), shaking and mixing the mixture uniformly by a shaking table, standing the mixture, and performing vacuum suction filtration;
(3) extracting aluminum by an alkaline method: mixing the filter residue obtained in the step (1) after suction filtration, a calcium-based compound and a potassium-based compound, adding water, drying after wet grinding, burning, cooling, dissolving with water, mixing, and suction filtration;
(4) molding and processing: and (3) mixing the filtrate obtained after the suction filtration in the step (2) with the filter residue obtained after the suction filtration in the step (3), uniformly stirring, drying, and performing ball milling and molding processing to obtain the acid soil conditioner rich in medium and trace elements.
Further, in the step (1), the concentration of the nitric acid is 0.1-10 mol/L, the nitric acid is added to dissolve out heavy metals in the fly ash and convert the heavy metals into water-soluble heavy metals, and the water-soluble heavy metals are separated by filtering.
Further, in the step (1), the solid-liquid mixing ratio of the fly ash and the concentrated nitric acid is 1: 1-1: 20 g/mL.
Further, in the step (1), the time of the ultrasonic treatment is 1-30 min.
Through the operation of the step (1), the heavy metal in the fly ash is dissolved in the filtrate, and the extraction rate of the heavy metal reaches more than 60% after the filtration.
Further, in the step (2), the concentration of the sodium sulfide solution is 0.1-5 mol/L, and the water-soluble heavy metal in the filtrate obtained in the step (1) after suction filtration is converted into heavy metal sulfide precipitate by adding the sodium sulfide solution.
Further, in the step (2), the mixing volume ratio of the filtrate obtained after the suction filtration in the step (1) and the sodium sulfide solution is 1: 1-1: 100.
After the operation of the step (2), the precipitation rate of heavy metal precipitated into filter residue reaches more than 80%, and the heavy metal sulfide obtained by precipitation is treated as hazardous waste.
Further, in the steps (1) and (2), the shaking table is oscillated for 10-100 min in a shaking table with the rotating speed of 100-200 r/min.
Further, in the steps (1) and (2), the standing time is 1-10 h.
Further, in the steps (1) and (2), the vacuum filtration is carried out for 1-10 min under the vacuum environment of 0-0.1 MPa.
Further, in the step (3), the calcium-based compound is CaSO4And CaCO3In combination with (1)，CaSO4And CaMg (CO)3) 2Or CaSO4And Ca (OH)2Combinations of (a) and (b).
Further, in the step (3), the potassium-based compound is an aluminum extraction aid, and is KOH or K2CO3。
Further, in the step (3), the mixing mass ratio of the filter residue obtained after the suction filtration in the step (1), the calcium-based compound and the potassium-based compound is as follows: 30-70% of filter residue obtained after suction filtration in step (1), and CaCO3Or CaMg (CO)3) 2Or Ca (OH)220% -80% of KOH or K2CO3 20%~80%，CaSO4 20%~40%。
Further, in the step (3), the solid-to-liquid ratio of the solid material obtained by mixing the filter residue obtained in the step (1), the calcium-based compound and the potassium-based compound to water is 1: 1-1: 10 g/mL.
Further, in the step (3), the wet grinding time is 10 min-100 min.
Further, in the step (3), the drying is carried out at 105 ℃ for 30-300 min.
Further, in the step (3), the burning is carried out at 900-1200 ℃ for 0.5-2 h.
Further, in the step (3), the cooling is to room temperature.
Further, in the step (3), the ratio of the burned and cooled material to the water dissolved and mixed is 1: 1-1: 3 g/mL.
Further, in the step (3), the potassium-based compound is replaced by the equivalent amount of the sodium-based compound; the sodium-based compound is NaOH or Na2CO3。
And (3) an alkaline aluminum extraction operation process, wherein the aluminum in the fly ash is extracted through the operation of the step (3), and the aluminum extraction rate is not lower than 85%.
Further, in the filtrate obtained by extracting aluminum in the step (3), the aluminum in the filtrate is recycled through the operation steps of precipitation and ignition, and the method specifically comprises the following steps:
adding potassium into the filtrate obtained in the step (3) through suction filtrationCarbonate solution of sodium, and CO2Or adding sulfuric acid with the mass concentration of 2% -10%, adjusting the pH value of the filtrate to 6-8, and filtering to obtain precipitate Al (OH)3Then burning at 900-1200 ℃ for 0.5-2h to obtain Al2O3；
The concentration of the potassium carbonate solution or the sodium carbonate solution is 10-500 g/L.
Further, in the step (4), the mixing ratio of the filtrate obtained after the suction filtration in the step (2) and the filter residue obtained after the suction filtration in the step (3) is 1: 10-10: 1 mL/g.
Further, in the step (4), the stirring time is 10-100 min.
Further, in the step (4), the drying is carried out at 105 ℃ for 30-300 min.
Further, in the obtained acid soil conditioner, the water content is lower than 5%, the soluble silicon content is more than 15%, the soluble calcium content is more than 25%, the soluble potassium content is more than 4%, the soluble magnesium content is more than 5%, the soluble sodium content is more than 2%, the sulfur content is 5%, the total soluble components are not lower than 80%, and the pH value is 9-12.
Further, the particle size of the obtained acid soil conditioner is 0.5-2 cm.
Compared with the prior art, the invention has the following advantages and beneficial effects:
(1) the production raw material of the invention is fly ash which is solid waste obtained after coal combustion, a large amount of aluminum contained in the fly ash is extracted, and residues are made into the acid soil conditioner to realize comprehensive utilization, thereby realizing more obvious economic benefit.
(2) According to the invention, the fly ash waste residue after aluminum extraction and the waste liquid after heavy metal removal are prepared into the mineral soil conditioner, so that secondary utilization of pollutants is realized, and the scientific concept of circular economic development and sustainable development is met.
(3) The mineral fertilizer prepared by the invention has complete types of medium elements, can achieve the effect of balanced fertilization, is used for adjusting the physicochemical property of acid soil, can obviously improve the content of the medium elements in the soil, and comprehensively improves the level of the medium and trace elements in the soil.
(4) The mineral fertilizer prepared by the invention is alkalescent, has obvious improvement effect on acid soil, obviously improves the soil environment, enhances the biological activity, improves the soil nutrient form and increases the nutrient solubility.
Drawings
FIG. 1 is a schematic diagram of a process flow for producing a medium trace element acid soil conditioner by using fly ash.
Detailed Description
The technical solutions of the present invention are further described in detail below with reference to specific examples and drawings, but the scope and implementation of the present invention are not limited thereto.
As shown in fig. 1, a schematic diagram of a process flow for producing a medium trace element acid soil conditioner by using fly ash according to the present invention is provided, which specifically comprises the following steps:
adding nitric acid into the fly ash according to the mass ratio of the nitric acid to the fly ash to dissolve out heavy metals, and filtering to obtain a filtrate containing the heavy metals and the fly ash from which the heavy metals are removed;
adding sodium sulfide into the obtained filtrate containing the heavy metals to precipitate the heavy metals, filtering, and taking the filtrate to obtain the filtrate after the heavy metals are removed;
extracting aluminum from the fly ash without heavy metals by an alkaline method to obtain residues; and slowly adding the residues into the filtrate from which the heavy metals are removed, fully shaking and mixing, drying to reduce the water content to 5%, performing ball milling and molding to obtain the secondary element acid soil conditioner, and packaging into bags.
According to the process flow shown in figure 1, the medium trace element acid soil conditioner is produced by utilizing fly ash.
Example 1
100 ten thousand tons of coal ash are produced annually in a thermal power plant of inner Mongolia, wherein the content of aluminum oxide is up to 47wt%, the content of silicon dioxide is 37.67 wt%, the content of potassium oxide is 0.42 wt%, the content of calcium oxide is 2.15 wt%, the content of ferric oxide is 1.375 wt%, and the content of heavy metals is as follows: lead content 21.73mg/kg, zinc content 12.1mg/kg, mercury content 0.74mg/kg, and copper content 7.97 mg/kg.
The process flow comprises the following steps:
(1) mixing the fly ash and nitric acid with the concentration of 0.1mol/L according to the material-liquid ratio of 1:1g/mL, carrying out ultrasonic treatment for 10min, oscillating in a shaking table at the rotating speed of 150r/min for 55min to disperse uniformly, standing for 10h, wherein the heavy metal dissolution rate is as follows: the mercury content reaches 87%, the copper content reaches 83%, the zinc removal rate reaches 84%, and the lead content reaches 66%; vacuum filtering under-0.05 MPa for 5.5 min;
(2) adding a sodium sulfide solution with the concentration of 1mol/l (the volume ratio of the sodium sulfide solution to the filtrate is 1: 1) into the filtrate obtained after the suction filtration in the step (1), shaking the mixture by a shaking table at the rotating speed of 200r/min for 55min, uniformly mixing, standing for 5.5h, and carrying out vacuum suction filtration for 10min under the vacuum condition of-0.05 MPa; the precipitation rate of copper, mercury and lead in the filtrate obtained after the suction filtration in the step (2) reaches 90 percent;
(3) mixing the filter residue obtained after the suction filtration in the step (1), calcium sulfate, calcium hydroxide and potassium hydroxide, wherein the mixing mass ratio is as follows: 30% of filter residue obtained after suction filtration in the step (1), 25% of calcium sulfate, 20% of calcium hydroxide and 25% of potassium hydroxide; adding water (the material-liquid ratio of the mixture to the water is 1:5.5 g/mL) into the obtained mixture, wet-grinding for 55min, drying at 105 ℃ for 30min, burning the dried sample at 900 ℃ for 0.5h, cooling after burning, dissolving in water according to the ratio of 1:1g/mL, mixing, and suction-filtering;
adding 5% sulfuric acid into the filtrate to adjust pH to 8, and filtering to obtain precipitate Al (OH)3Firing at 900 ℃ for 0.5h to obtain Al2O3；
(4) And (3) mixing the filtrate obtained after the suction filtration in the step (2) with the filter residue obtained after the suction filtration in the step (3) according to the material-liquid ratio of 10:1g/mL, shaking the mixture in a shaking table at the rotating speed of 200r/min for 10min, uniformly mixing the mixture, drying the mixture at 105 ℃ for 60min, and performing ball milling and molding processing to obtain the acid soil conditioner rich in medium and trace elements.
And the following components are detected by a third party: the produced acid soil conditioner has the soluble components of 80 wt%, soluble sulfur content of 5 wt%, soluble silicon content of 15 wt%, soluble calcium content of 25 wt%, soluble magnesium content of more than 5 wt%, soluble potassium content of 4 wt%, soluble sodium content of 2wt% and pH of 10.5, and is a nutritional acid soil conditioner containing various medium elements.
Example 2
60 ten thousand tons of annual fly ash are produced in a certain thermal power plant of the cucurbit island, wherein the content of alumina is 40 wt%, the content of silicon dioxide is 42.67 wt%, the content of potassium oxide is 0.72 wt%, the content of calcium oxide is 3.15 wt%, the content of ferric oxide is 2.375 wt%, and the content of heavy metals is as follows: the lead content is 55.73mg/kg, the zinc content is 21.1mg/kg, the mercury content is 0.34mg/kg, and the copper content is 5.97 mg/kg.
The process flow comprises the following steps:
(1) mixing fly ash and nitric acid with the concentration of 0.55mol/L according to the material-liquid ratio of 1: after 10.5g/mL of the mixture is mixed, after ultrasonic treatment is carried out for 20min, the mixture is vibrated in a shaking table with the rotating speed of 100r/min for 10min to be uniformly dispersed, and the mixture is kept stand for 1h, wherein the heavy metal dissolution rate is as follows: the mercury reaches 92 percent, the copper reaches 80 percent, the zinc removal rate reaches 80 percent, and the lead reaches 78 percent; vacuum filtering under 0MPa for 1 min;
(2) adding a sodium sulfide solution with the concentration of 3mol/l (the volume ratio of the sodium sulfide solution to the filtrate is 1: 5.5) into the filtrate obtained after the suction filtration in the step (1), shaking the mixture by a shaking table at the rotating speed of 100r/min for 100min, uniformly mixing, standing for 1h, and carrying out vacuum suction filtration for 5.5min under the vacuum condition of-0.1 MPa; the precipitation rate of copper, mercury and lead in the filtrate obtained after the suction filtration in the step (2) reaches 85 percent;
(3) mixing the filter residue obtained after the suction filtration in the step (1), calcium sulfate, calcium hydroxide and sodium hydroxide, wherein the mixing mass ratio is as follows: 35% of filter residue obtained after suction filtration in the step (1), 28% of calcium sulfate, 20% of calcium hydroxide and 22% of sodium hydroxide; adding water (the material-liquid ratio of the mixture to the water is 1:1 g/mL) into the obtained mixture, wet-grinding for 10min, drying at 105 ℃ for 60min, burning the dried sample at 1050 ℃ for 1.25h, cooling after burning, dissolving in water according to the ratio of 1:2g/mL, mixing, and suction-filtering;
adding 4% sulfuric acid into the filtrate to adjust pH to 7.2, and filtering to obtain precipitate Al (OH)3Burning at 1050 deg.C for 1.25h to obtain Al2O3；
(4) And (3) mixing the filtrate obtained after the suction filtration in the step (2) with the filter residue obtained after the suction filtration in the step (3) according to the material-liquid ratio of 1:1g/mL, shaking the mixture in a shaking table at the rotating speed of 150r/min for 55min, uniformly mixing the mixture, drying the mixture at 105 ℃ for 60min, and performing ball milling and molding processing to obtain the acid soil conditioner rich in medium and trace elements.
And the following components are detected by a third party: the produced acid soil conditioner contains 82 wt% of soluble components, wherein the content of soluble sulfur is 4 wt%, the content of soluble silicon is 17 wt%, the content of soluble calcium is 22 wt%, the content of soluble magnesium is more than 5.7 wt%, the content of soluble potassium is 2wt%, the content of soluble sodium is 5 wt%, and the acid soil conditioner contains various trace elements such as iron, zinc, manganese and the like, the pH value of the acid soil conditioner is 11.2, and the synthesized product is a nutritional acid soil conditioner containing various medium elements.
Example 3
30 ten thousand tons of coal ash are produced annually in a thermal power plant in Hebei province, wherein the content of aluminum oxide is 45 wt%, the content of silicon dioxide is 46.67 wt%, the content of potassium oxide is 0.92 wt%, the content of calcium oxide is 6.15 wt%, the content of ferric oxide is 0.375 wt%, and the content of heavy metals is as follows: lead content 10.73mg/kg, zinc content 30.1mg/kg, copper content 7.64 mg/kg.
The process flow comprises the following steps:
(1) mixing fly ash and nitric acid with the concentration of 1mol/L according to the material-liquid ratio of 1: after 20g/mL of the mixture is mixed, ultrasonic treatment is carried out for 30min, the mixture is uniformly dispersed by shaking for 100min in a shaking table with the rotating speed of 200r/min, standing is carried out for 5.5h, and the heavy metal dissolution rate is as follows: the mercury content reaches 89%, the copper content reaches 86%, the zinc removal rate reaches 78%, and the lead content reaches 92%; vacuum filtering under-0.1 MPa for 10 min;
(2) adding a sodium sulfide solution with the concentration of 5mol/l (the volume ratio of the sodium sulfide solution to the filtrate is 1: 10) into the filtrate obtained after the suction filtration in the step (1), shaking the mixture for 10min by a shaking table at the rotating speed of 150r/min, uniformly mixing, standing for 10h, and carrying out vacuum suction filtration for 1min under the vacuum condition of 0 MPa; the precipitation rate of copper, mercury and lead in the filtrate obtained after the suction filtration in the step (2) reaches 85 percent;
(3) mixing the filter residue obtained after the suction filtration in the step (1), calcium sulfate, calcium hydroxide and sodium hydroxide, wherein the mixing mass ratio is as follows: 35% of filter residue obtained after suction filtration in the step (1), 28% of calcium sulfate, 20% of calcium hydroxide and 22% of sodium hydroxide; adding water (the material-liquid ratio of the mixture to the water is 1:10 g/mL) into the obtained mixture, wet-grinding for 100min, drying at 105 ℃ for 60min, burning the dried sample at 1200 ℃ for 2h, cooling, dissolving in water according to the ratio of 1:3g/mL, mixing, and suction-filtering;
adding 4% sulfuric acid into the filtrate to adjust pH to 7.2, and filtering to obtain precipitate Al (OH)3Firing at 1200 ℃ for 2h to obtain Al2O3；
(4) And (3) mixing the filtrate obtained after the suction filtration in the step (2) with the filter residue obtained after the suction filtration in the step (3) according to the material-liquid ratio of 1:10g/mL, shaking the mixture in a shaking table at the rotating speed of 200r/min for 100min, uniformly mixing, drying at 105 ℃ for 60min, and performing ball milling and molding processing to obtain the acid soil conditioner rich in medium and trace elements.
And the following components are detected by a third party: the produced acid soil conditioner has the soluble components of 84 wt%, soluble sulfur content of 4.2 wt%, soluble silicon content of 16.5 wt%, soluble calcium content of 23 wt%, soluble magnesium content of more than 5.4 wt%, soluble potassium content of 2.6wt%, soluble sodium content of 5 wt%, various trace elements such as iron, zinc, manganese and the like, and the pH value of the acid soil conditioner is 10.8, and the synthesized product is a nutritional acid soil conditioner containing various medium elements.
The above embodiments are merely preferred embodiments of the present invention, which are intended to be illustrative and not limiting, and any changes, substitutions, combinations, simplifications, modifications, etc. made by those skilled in the art without departing from the spirit and principle of the present invention shall be included in the scope of the present invention.
Claims (9)
1. A method for producing a medium trace element acid soil conditioner by using fly ash is characterized by comprising the following steps:
(1) mixing the fly ash and nitric acid, performing ultrasonic treatment and shaking table vibration to disperse the mixture uniformly, standing the mixture, and performing vacuum filtration; the concentration of the nitric acid is 0.1-1 mol/L; the solid-liquid mixing ratio of the fly ash to the nitric acid is 1: 1-1: 20 g/mL;
(2) adding a sodium sulfide solution into the filtrate obtained after suction filtration in the step (1), shaking and mixing the mixture uniformly by a shaking table, standing the mixture, and performing vacuum suction filtration, wherein the mixing volume ratio of the filtrate obtained after suction filtration to the sodium sulfide solution is 1: 1-1: 10; the concentration of the sodium sulfide solution is 0.1-5 mol/L;
(3) mixing the filter residue obtained in the step (1) after suction filtration, a calcium-based compound and a potassium-based compound, adding water, drying after wet grinding, burning, cooling, dissolving with water, mixing, and suction filtration;
(4) and (3) mixing the filtrate obtained after the suction filtration in the step (2) with the filter residue obtained after the suction filtration in the step (3), uniformly stirring, drying, and performing ball milling and molding processing to obtain the medium-trace element acidic soil conditioner.
2. The method according to claim 1, wherein in the step (1), the time of the ultrasonic treatment is 10-30 min.
3. The method according to claim 1, wherein in steps (1) and (2), the shaking table is shaken for 10-100 min in a shaking table rotating at a speed of 100-200 r/min; the standing time is 1-10 h; and the vacuum filtration is carried out for 1-10 min under the vacuum environment of 0-0.1 MPa.
4. The method according to claim 1, wherein in step (3), the calcium-based compound is CaSO4And CaCO3A combination of (1), CaSO4And CaMg (CO)3) 2Or CaSO4And Ca (OH)2A combination of (1); the potassium-based compound is KOH or K2CO3(ii) a The mixing mass ratio of the filter residue obtained after the suction filtration in the step (1), the calcium-based compound and the potassium-based compound is as follows: 30-70% of filter residue obtained after suction filtration in the step (1), CaCO3Or CaMg (CO)3) 2Or Ca (OH)220% -80%, KOH or K2CO320％～80％，CaSO420％～40％。
5. The method according to claim 1, wherein in the step (3), the solid-to-liquid ratio of the solid material obtained by mixing the filter residue obtained by suction filtration in the step (1), the calcium-based compound and the potassium-based compound to water is 1: 1-1: 10 g/mL.
6. The method according to claim 1, wherein in the step (3), the wet milling time is 10min to 100 min; firing at 900-1200 ℃ for 0.5-2 h; the cooling is to cool to normal temperature; the ratio of the burned and cooled material to water dissolved and mixed is 1: 1-1: 3 g/mL.
7. The method according to claim 1, wherein in step (3), an equal amount of a sodium-based compound is used instead of a potassium-based compound; the sodium-based compound is NaOH or Na2CO3。
8. The method according to claim 1, wherein in the step (4), the mixture ratio of the filtrate obtained after the suction filtration in the step (2) and the filter residue obtained after the suction filtration in the step (3) is 1: 10-10: 1 mL/g; the stirring time is 10-100 min.
9. The medium trace element acid soil conditioner prepared by the method of any one of claims 1 to 8, wherein the acid soil conditioner has a water content of less than 5 wt%, a soluble silicon content of 15 wt% or more, a soluble calcium content of more than 25 wt%, a soluble potassium content of more than 4 wt% or a soluble sodium content of more than 2wt%, a sulfur content of 5 wt%, a total soluble component of not less than 80 wt%, and a pH of 9 to 12; the particle size of the acidic soil conditioner is 0.5-2 cm.
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| CN111019662B (en) * | 2019-12-20 | 2022-05-24 | 华南理工大学 | Soil water-retaining agent produced by using aluminum ash and preparation method thereof |
| CN112335804A (en) * | 2020-11-05 | 2021-02-09 | 宁波华颐生物科技有限公司 | Preparation method of natural active mineral substance beverage |
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101028936A (en) * | 2007-01-26 | 2007-09-05 | 长安大学 | Method for extracting alumin from aluminous fly-ash and method for producing cement from fag end |
| CN102476820A (en) * | 2010-11-25 | 2012-05-30 | 中国科学院过程工程研究所 | Method for extracting alumina from coal ash through wet process |
| CN107188766A (en) * | 2017-07-26 | 2017-09-22 | 山东乡里乡亲互联网科技股份有限公司 | A kind of coal ash for manufacturing for silicon composite fertilizer method |
| CN108276228A (en) * | 2018-01-16 | 2018-07-13 | 航天凯天环保科技股份有限公司 | One kind being used for the fertilizer and preparation method thereof of Cr (VI) contaminated soil remediations and improvement |
| CN108424207A (en) * | 2018-06-04 | 2018-08-21 | 国家能源投资集团有限责任公司 | Flyash acid system residue of aluminum-extracted prepares the method containing silicon potassium compound fertilizer and the utilization method containing silicon potassium compound fertilizer and flyash |
| CN108484334A (en) * | 2018-06-18 | 2018-09-04 | 贵州益寿农业科技有限公司 | A kind of Special fertilizer for oil tea and its processing technology |
-
2018
- 2018-09-18 CN CN201811083790.9A patent/CN109369286B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101028936A (en) * | 2007-01-26 | 2007-09-05 | 长安大学 | Method for extracting alumin from aluminous fly-ash and method for producing cement from fag end |
| CN102476820A (en) * | 2010-11-25 | 2012-05-30 | 中国科学院过程工程研究所 | Method for extracting alumina from coal ash through wet process |
| CN107188766A (en) * | 2017-07-26 | 2017-09-22 | 山东乡里乡亲互联网科技股份有限公司 | A kind of coal ash for manufacturing for silicon composite fertilizer method |
| CN108276228A (en) * | 2018-01-16 | 2018-07-13 | 航天凯天环保科技股份有限公司 | One kind being used for the fertilizer and preparation method thereof of Cr (VI) contaminated soil remediations and improvement |
| CN108424207A (en) * | 2018-06-04 | 2018-08-21 | 国家能源投资集团有限责任公司 | Flyash acid system residue of aluminum-extracted prepares the method containing silicon potassium compound fertilizer and the utilization method containing silicon potassium compound fertilizer and flyash |
| CN108484334A (en) * | 2018-06-18 | 2018-09-04 | 贵州益寿农业科技有限公司 | A kind of Special fertilizer for oil tea and its processing technology |
Non-Patent Citations (5)
| Title |
|---|
| 淮南粉煤灰中重金属元素形态分析;刘陪陶等;《能源技术与管理》;20080229(第1期);第64-66页 * |
| 硝酸脱除褐煤粉煤灰中的砷;韩大捷等;《过程工程学报》;20180831;第18卷(第4期);第716-720页 * |
| 粉煤灰中重金属元素浸出特性研究;赵文霞等;《粉煤灰综合利用》;20060630(第3期);第5-6页 * |
| 酸性红壤条件下钾硅钙肥对茄子生长及土壤性状的影响;程凤娴等;《现代农业科技》;20171031(第20期);第68-71页 * |
| 高砷烟尘氢氧化钠−硫化钠碱性浸出脱砷;易宇等;《中国有色金属学报》;20150331;第25卷(第2期);第06-813页 * |
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