301results about How to "Achieving a circular economy" patented technology

The invention discloses a method used for the preparation of microcrystalline glass by use of blast furnace slag, wherein blast furnace slag is crushed and sifted out and then is mixed with 0 to 10 wt percent of feldspar and 0 to 5 wt percent of zirconite to make mixed powder material with the weight proportion of blast furnace slag no less than 85 percent; then, the mixed powder material is made into slurry through ball milling mixing and agglomerant is added in after the slurry is dried to complete granulation; and finally, microcrystalline glass is made through direct tabletting crystallizing sintering. The method has the advantages that: (1) ironmaking blast furnace slag is adopted as main material with the addition amount of the blast furnace slag reaching more than 85 percent, which not only saves resources and reduces pollution, but also realizes cycle economy; (2) cheap silicate materials including zirconite and feldspar are adopted as additives; (3) powder tabletting sintering method is adopted to make microcrystalline glass, thereby omitting the complex process of casting moulding after high-temperature fusion of glass or sintering after fusion water quench in the prior glass process and sintering process.

A method of repairing mine ecological environment comprises the treatment of mine environment contamination, wherein the tailings, the barren rock, the smelting slag, the waste water from ore cleaning, the waste water from smelting, the acid mine drainage and the ore yard leachwater which are generated from mine development are collected into the tailings storage, at the same time, sludge and organic matter capable of being degradated by microbiology are added therein, and then the tailings storage is given an anaerobic environment artificially, so that, under the action of microbiology and sulfate reducing bacteria, sulfur ion is generated and the pH value of the tailings storage is increased, a plurality of heavy metal ions are cured and settled by sulfur ion to avoid migration, a biomembrane layer-sulfate reducing bacteria reducing-induction biomineralization precipitation composite geochemical barrier is generated in the tailings storage. The repairing of mine ecological environment is realized by the treatment of mine environment contamination. The present invention can be used for tailings storage pollution prevention in tour, and can be used for closing the repairing of mine ecological environment, or can be used for designing new tailings storage by using the technology of the present invention.

A method for extracting succinic acid from fermentation broth through cation resin exchange belongs to the biochemical technical field. The method comprises the following steps that fermentation broth undergoes heated centrifugal filtration or membrane filtration so as to eliminate thalli; sodium carbonate is added in the clear solution to generate magnesium carbonate precipitation; a filter cake is reclaimed after filtration; then, the filtrate flows through a cation resin column, and the effluent is succinic acid solution; a succinic acid product is obtained after decoloring, concentration and crystallization; the cation resin column is eluted by ammonium carbonate after exchange so as to obtain sodium bicarbonate effluent; sodium salt is reclaimed and reused in fermentation broth treatment after ammonia is eliminated by heating; furthermore, resin regeneration can be realized by sulphuric acid through a conventional method, and the generated (NH4)2 SO4 can be used as a fertilizer. The method does not need to carry out acidification for the filtrate, and has the advantages of short technological line and high yield, thereby realizing element cycle economy. The invention provides a method for extracting succinic acid from microorganism fermentation broth with simple operation and economical efficiency.

The invention relates to a rice seedling raising matrix and a production method thereof, and belongs to a seedling raising matrix and a production method thereof. The matrix is prepared by the following formula and method that: the formula comprises 50 to 70 percent of crushed corn stalk of 40 to 60 meshes, 10 to 30 percent of crushed rice straw of 40 to 60 meshes, 5 to 15 percent of farmyard manure of 40 to 60 meshes and 5 to 15 percent of industrial slag powder of 40 to 60 meshes; and the method comprises material preparation, raw material crushing, fermentation, mixing, drying and stirring. The method for producing the seedling raising matrix by using the raw materials such as straws, farmyard manure, slag and the like thoroughly solves the problems of vegetation destroy caused by taking soil for raising seedlings and difficult soil taking, reduces the production processes of taking soil, sieving soil, regulating acid, stirring fertilizers, stirring drugs and the like, and lightens the labor intensity of rice farmers. The method can be applied in rice seedling raising and vegetable and flower seedling raising production, and is a new effective path for making full use of straw resources and realizing energy conservation, emission reduction and agricultural circular economy.

The invention relates to an environmentally-friendly plate for raising rice seedlings and a rice seedling production method, which belong to a rice seedling raising medium and a production method. The plate contains the following raw materials in percentage by weight: 40 to 60 mesh crushed coin straw 60-80, industrial paper pulp processing waste slag liquid 15-25, and 40 to 60 mesh industrial fluidized bed furnace ground slag 5-15. The method comprises: material preparation, raw material crushing, fermentation, mixing, material drying, stirring, pulping, mold loading, compression molding, demoulding and drying. The plate and the production method have the advantages of reducing damages to vegetation, namely plough layer surface soil, solving the problem of difficult soil digging, developing and utilizing straw resources, realizing energy conservation and emission reduction, integrating the medium and the plate, replacing a seedling raising plate and being suitable for the standardization of mechanical sowing, mechanical planting and seedling raising.

The invention relates to a recovery and comprehensive utilization method of heavy metals in stainless steel pickling wastewater sludge and discloses a method for recovering and recycling nickel and chrome in sludge generated during the treatment process of stainless wastewater. The method comprises the following steps: leading waste liquid during the pickling process to be directly used for leaching metal ions in the sludge to save the consumption of reagents; adding a certain quantity of acid or alkali in each reaction tank through arranging a plurality of reaction tanks; controlling a pH value; effectively separating various matters according to different solubility of inorganic compounds; researching and developing a recycling technology of the heavy metals in the stainless steel industrial sludge, wherein the recovery efficiency of the heavy metals like the chrome and the nickel is high; leading the recovered heavy metals to be used for smelting stainless steel; leading recovered iron to be used for preparing an efficient flocculating agent; and leading the flocculating agent to be used for sewage treatment to realize sewage reuse and save the treatment cost. The invention has the advantages of simple process and easy operation, as well as popularization and application.

The invention relates to a treating method for energy regeneration, resource recovery and pollution free of restaurant garbage, which comprises the steps that separated liquid material is pumped into a swage concentrating pool; then the concentrated liquid material is discharged into a regulating and pretreating pool, in which methane bacteria are inoculated; the pretreated liquid material is discharged into an anaerobic fermentation pool, in which anaerobic bacteria groups are added so that methane gas is generated and the overflowing liquid material from the anaerobic fermentation pool is led to enter an aerobic aerated pool for aerobic reaction; the liquid material after the aerobic reaction is discharged into a sedimentation tank for sedimentation. In the comprehensive utilization of 'swill', the disposing method of the invention carries out anaerobic fermentation and aerobic aerated biochemical treatment to transform part of the energy in the swill into bio-energy which is then transformed into heat energy and finally into electrical energy that is connected with power grid for use. The separated solid material is smashed, dried, sterilized, dehydrated and then added with Chinese herbal medicine to be processed into Chinese herbal medicine compound feeds and fertilizers; meanwhile, the treatment of energy regeneration, resource recovery and pollution free of restaurant garbage for restaurant garbage is realized.

The invention relates to a method for efficiently preparing cotton based mesoporous activated carbon fiber. The method comprises a step (1) of washing cotton, placing the cotton in a hydrothermal reaction kettle, performing heating to 150-200 DEG C at the heating rate of 5-30 DEG C / min, performing hydrothermal carbonization, performing heat preservation for 1-3 hours and then performing cooling to room temperature; a step (2) of dipping carbonization materials obtained from the step (1) into activator solution, performing microwave-ultrasonic joint dipping for 5-30 minutes and then performing filtration, sending filtration materials to a microwave heating device, performing activation for 5-15 minutes at 250-350 DEG C and then stopping microwave output, and a step (3) of washing the activated materials to be neutral and performing drying to obtain the activated carbon fiber. According to the method, the characteristics of microwave inner heating and selective heating are fully utilized, the technological process is simple, the activation temperature is only 250-350 DEG C, the activation time is only 5-15 minutes, the mesoporous proportion of the activated carbon fiber of the product reaches 50-90%, and the adsorptive property is good.

A purpose of the invention is to provide a sodium hydrosulfide preparation method utilizing hydrogen sulfide exhaust. The invention not only can resolve the treatment problems of the three wastes of barium carbonate and strontium carbonate enterprises, but also can reuse calcium sulfate, the byproduct from the preparation of sodium hydrosulfide, as raw materials for other chemical production, which realizes the recycling of raw materials and products. The production ability of the traditional alkali solution absorbing method, the absorbing adaptability of mixed hydrogen sulfide exhaust and the sodium hydrosulfide preparation rate are enhanced; while the production cost is reduced and the exhaust can be discharged according to standards after being absorbed by alkali solution. The invention resolves the problems of low absorption rate of hydrogen sulfide gas, low production efficiency of preparation of sodium hydrosulfide, large investment of technical devices and difficulty of solid phase recycling existing in a method of 'one step for preparation of sodium hydrosulfide' using hydrogen sulfide gas, calcium hydroxide and sodium sulfide as raw materials.

The invention relates to a rice seedling raising medium and a rice seedling production method and belongs to a rice seedling raising medium and a rice seedling production method. The medium is prepared by a formula comprising 60 to 80 percent of 40 to 60 mesh crushed coin straw, 15 to 25 percent of industrial paper pulp processing waste slag liquid and 5 to 15 percent of 40 to 60 mesh industrial fluidized bed furnace ground slag and by a method comprising material preparation, raw material crushing and fermentation, wherein the fermentation is to add 0.5 kilogram of mixed solution of saccharomycetes and lactic acid bacteria in a ratio of 0.35:0.65 into each 1,000 kilograms of the crushed corn straw, mix the solution, dry the mixture and stir the mixture. In the invention, the problem of damaging vegetation during soil digging for raising seedlings and the problem of difficult soil digging are solved, the production processes of soil digging, soil sieving, acid regulation, fertilizer mixing, medicament mixing and the like are avoided, and the labor intensity of rice farmers is relieved. In the invention, a new approach is provided for utilizing straw resource, realizing energy conservation, emission reduction and agricultural circular economy.

The invention discloses a technology for preparing microcrystal glass by utilizing blast furnace water granulated slag and coal ash, used for solving the problems that technology is complex, production cost is high, waste residue utilization factor is low and large scale commercial production is not benefited in the existing microcrystal glass preparation technology. The technology includes the following processes: screening, blast furnace water granulated slag is smashed and screened, thus obtaining water granulated slag powder less than 200 meshes; material mixing, coal ash with weight percent less than or equal to 20% and auxiliary solvent with weight percent less than or equal to 10% are added into the water granulated slag powder, the balance is water granulated slag powder, thus obtaining mixed powder material; pulping, the mixed material is pulped and then dried, thus obtaining wet material with moisture content less than or equal to 5%; pelleting, binder less than or equal to 5% weight of the wet material is added into the wet material, thus obtaining granules; tabletting, crystallizing and sintering, the granules are subject to tabletting, crystallizing and sintering, thus obtaining waste residue microcrystal glass. The invention has the characteristics of simple technology, low production cost and high waste residue utilization factor.

The invention relates to a complete cycle preparation method of lithium iron phosphate by using lithium ores as a lithium source, comprising the following steps: carrying out calcining, acidifying, leaching, purifying and separating on the lithium ores to obtain a primary lithium liquid, carrying out conversion and refrigeration, filtering and washing, evaporative concentration on the primary lithium liquid to obtain a lithium liquid for synthesis, letting the lithium liquid for synthesis, a ferrite solution, and a phosphor source solution be subject to liquid phase synthesis, and calcining to obtain the carbon coated lithium iron phosphate. According to the invention, cooling crystallization, separation, drying and other steps in the preparation of lithium iron phosphate with lithium ores are left out, and the byproducts obtained by evaporative concentration, filtering and separating are recycled, so that the utilization rate of resource is increased, and the cost is saved; and the prepared lithium iron phosphate has the characteristics of high purity, excellent electrochemical performance and the like, so that the circular economy is realized.

The present invention discloses a self-compacting concrete prepared from iron ore tailings, and a preparation method thereof. The self-compacting concrete is prepared through adding 38.00-46.00% of a coarse aggregate, 23.00-37.00% of a fine aggregate, cement, 15-24% of a cementing material and 0.30-0.48% of an additive to water. The coarse aggregate is prepared through mixing crushed stones with particle sizes of 5-20 mm. The fine aggregate is the mixed sands prepared from iron ore tailings and machine-made sands or natural sands, wherein the mixed sands meet the technical requirements of thesands in the region II, preferably that a mass ratio of the iron ore tailings to the machine-made sands or the natural sands is 3:7-7:3. The cementing material is a mixture, wherein the mixture comprises cement, fly ash and ground slag powder. A mass ratio of the water to the cementing material is 0.30-0.50. The additive is a mixture, wherein the mixture comprises a water reducing agent and a tackifier, the water reducing agent is a polycarboxylic superplasticizer, the tackifier comprises a cellulose polymer or an amide polymer. With the present invention, the damage to the ecology environment due to the natural sand mining is reduced; the damage to the environment due to the iron ore tailings is reduced; the waste can be utilized; a purpose of reutilization of the resource is achieved; with adopting the iron ore tailings, the concrete cost can be substantially reduced, and significant social benefits and economic benefits are provided.

The invention discloses an integrated technology of thermal decomposing, dry distilling and gasifying sludge and preparing of ceramsite. By utilizing the method disclosed by the invention to process the sludge in a city, retained heat in the sludge in the city and utilization values of inorganic components can be fully achieved; and moreover, a lightweight heat insulation building material can be obtained while the sludge is processed in a harmless manner; and harmlessness, reduction and resource utilization of the sludge of a sewage plant in the city can be achieved.

The invention discloses an organic leaf surface fertilizer rich in organic selenium and vitamins and a preparation method for the organic leaf surface fertilizer. The organic leaf surface fertilizer rich in the organic selenium and the vitamins comprises the raw materials in parts by weight: 40-60 parts of selenium-enriched bombyx mori, 40-60 parts of selenium-enriched plant waste, 40-60 parts of selenium-enriched edible mushroom waste, 40-60 parts of sodium selenite, 20-30 parts of vitamins and 1-10 parts of a composite fungicide. The selenium-enriched bombyx mori, the selenium-enriched plant waste and the selenium-enriched edible mushroom waste of the fertilizer can supply selenium elements and also supply animal proteins, plant proteins and microorganism proteins and are fermented by composite bacteria to polypeptide combined with the selenium elements. Therefore, the fertilizer can be used for supplying enough organic selenium and beneficial substances such as microorganisms and probiotics to the growth of crops; a large amount of waste is turned into treasures, so that social and natural resources are saved, the environment is protected, and cyclic economy is realized.

The invention discloses three-laminated composite board type full-nutritional rice seedling breeding bedding and a preparation method thereof and relates to rice seedling breeding bedding and a preparation method thereof. The problems that existing seedling breeding bedding is poor in water-retaining property, fertilizer efficiency in the later period of seedling breeding is poor, strength is low, and the existing seedling breeding bedding is not suitable for being transported and carried are solved. The seedling breeding bedding is divided into three layers from top to bottom, the middle layer is a core layer, and the surface layers are located on the two sides of the core layer. The preparation method comprises the following steps that (1), straw is cut into sections; (2), steaming and softening are conducted; (3), the straw is ground and kneaded to be in a fiber shape and is dried; (4), mixing is conducted; (5), paving is conducted; and (6), hot-pressing is conducted. According to the three-laminated composite board type full-nutritional rice seedling breeding bedding (as shown in figure 1) produced through the preparation method, when no water is absorbed by the three-laminated composite board type full-nutritional rice seedling breeding bedding, the static bending intensity is 21-22.8 MPa, and the internal bonding strength is 0.35-0.40 MPa; and the three-laminated composite board type full-nutritional rice seedling breeding bedding is high in strength, not prone to breakage or damage and easy to cut and can be manufactured to be in different shapes.

The invention relates to a method for recycling calcium carbonate from free gypsum dehydration in co-production. The method comprises the steps of taking carbon monoxide as a reducing agent to replace a solid carbon reducing agent to prepare calcium sulfide from desulfurization slag; further generating SO2; taking SO2 as sulphuric acid to produce a feed gas to recycle sulfur resources; at the same time, adding metal oxide, a rare earth compound, coupling metal oxide, etc. as catalysts; and promoting the reduction reaction by catalytic reduction method. Limestone obtained after desulfurization is returned to be used as a desulfurizer so as to recycle the free gypsum dehydration, and to reduce natural gypsum dehydration mining and protect the environment. The method is suitable for the free gypsum dehydration produced in a coal-fired industry, and for the free gypsum dehydration produced by desulfurization of kiln gas.

The invention relates to iron tailing super-fine sand concrete and discloses concrete prepared by taking mixed sands consisting of iron tailing super-fine sand and machine-made sands as a fine aggregate, and belongs to the technical field of iron tailing sand building materials. The concrete is prepared from the following components in percentage by mass: 8-15% of cement, 21-34% of iron tailing mixed sands, 44-49% of gravels, 5-7% of an admixture, 7.2-8.3% of water and 1.6-2.2% of an efficient pumping agent for concrete based on the sum of mass of the cement and the admixture. The water-binder ratio of the prepared concrete is 0.75-0.36 and the strength grade is C20-C50. The iron tailing super-fine sand concrete provided by the invention can reduce the environmental pollution caused by iron tailings, reduce the exploitation quantity and exploitation energy consumption of natural sands and lower the production cost of the concrete, and has obvious economic and social benefits.

The invention provides a resource utilization method of kitchen waste. The resource utilization method comprises the following steps: a. carrying out high-temperature instantaneous sterilization on the collected kitchen waste and then storing the sterilized kitchen waste; b. removing free water and oil out of the kitchen waste; c. carrying out oil-water separation and exchange reaction on a liquid phase so as to prepare biodiesel, and then carrying out waste water treatment; d. carrying out magnetic separation and further dewatering; e. processing with a catalyst; f. transforming combustion heat energy; and g. removing colloid out of the liquid phase through oil-water separation so that the colloid can be taken as fuel oil, and then carrying out waste water treatment on an aqueous phase. The resource utilization method has the beneficial effects that the kitchen waste is fully recycled so as to solve the problems of waste water, waste gas and the like; the effects of high efficiency, energy conservation, low consumption and environmental protection are realized; wastes are changed into valuables; and the treatment cost is low, thus achieving the purpose of circular economy.

The invention relates to a method for recycling sulfur from acid gases containing hydrogen sulfide, comprising the following steps: (a) air supply; (b) acid gas pretreatment; (c) mixture; (d) primary direct catalytic oxidation; (e) primary sulfur condensation; (f) process gas reheating; (g) secondary direct catalytic oxidation; (h) secondary sulfur condensation; (i) sulfur re-separation; (j) degasification in a liquid sulfur tank; and (k) tail gas burning. When the volume concentration of H2S in the acid gases in the prior art is 1-15%, the recycle rate of sulfur can reach over 99% by the method of the invention, and the emission load of H2S in the acid gases processed by the method of the invention meets the emission requirement of Integrated Emission Standard of Air Pollutants (GB16297-1996).

This invention relates to a method for purifying eutrophic water body by using water plant, particularly duck-weed and polycultured with other water plants. The adsorption, absorbing and biochemical reaction of said water plants are used for removing nitrogen, phosphorus and other pollutants. The plants occupies 70-90% of the surface of the water body. This invention has advantages of: simple operation, low management cost, obvious treatment effect, no secondary pollution, the water plants can be harvested as resource, being of a popularized treatment method for eutrophic water body.

The invention discloses an organic-selenium-enriched microorganism organic composite fertilizer and a preparation method thereof. The organic-selenium-enriched microorganism organic composite fertilizer comprises the raw materials in parts by weight: 40-60 parts of selenium-enriched bombyx mori, 40-60 parts of selenium-enriched plant waste, 40-60 parts of selenium-enriched edible mushroom waste, 40-60 parts of minerals, 20-30 parts of vitamins and 1-10 parts of a composite fungicide. The organic-selenium-enriched microorganism organic composite fertilizer can supply enough minerals such as organic selenium and beneficial substances such as microorganisms and probiotics to the growth of crops; meanwhile, the fertilizer can improve the soil, prevent diseases, and realize sterilization; a large amount of waste is turned into treasures, so that social and natural resources are saved, the environment is protected, and cyclic economy is realized. The organic-selenium-enriched microorganism organic composite fertilizer is one of the best fertilizers for producing pollution-free food, green food and organic food.

The invention discloses a cane sugar manufacture production system. The production system is characterized by comprising a cleaning system, a discoloring system, an evaporation system, a sugar boiling system and a purging and drying system; the system device comprises a pipeline filter, a mixed juice tank, a mixed juice pump, a static mixer, a heater, a rapid settling basin, a dosing storage tank, a filter press, a falling film evaporator, a condenser, a discoloring column, a bag filter, a sugar boiling crystallizing tank, a syrup tank, a help-crystallization box, a purging box, a conveyor, a drying machine, a gas-liquid separator, a honey jar, a clear juice pump, a syrup pump, a circulating pump and a vacuum pump. According to the cane sugar manufacture production system, a stove drying system and a carbonation system in the original sugar refining design are canceled, a novel process is adopted, novel industrial equipment is introduced, and the system can serve as a scientific research platform for performing a novel cane sugar manufacture process or an industrial production line for producing raw sugar, primary white granulated sugar, high-grade sugar and refined sugar.

The invention discloses a method for preparing sodium chromate by mixing chromite and ferrochrome and a device for the method. The method comprises the following steps: measuring and mixing chromite and ferrochrome with sodium carbonate, sodium nitrate and sodium peroxide; pelleting the mixture with extracted liquid sodium chromate in a pelletizer; drying in a drier; returning part of the clinker to a flame kiln after the material is dried and cooled, so that chromite and ferrochrome are decomposed and oxidized in the form of fused liquid phase in molten salts so as to obtain the clinker of sodium chromate; and continuously soaking, filtering and cleaning after the clinker is cooled so that a chromium chemical primary product of liquid sodium chromate is obtained, wherein the flame kiln comprises a U-shaped kiln body, a partition wall and a low-position molten salt suction port, wherein the partition wall and the low-position molten salt suction port are arranged in the U-shaped kiln body; one or more blowing oxygen lances and one or more charging holes are arranged at the top of the kiln body, and a smoke outlet is arranged on the upper side of the kiln; and one or more oxygen lances are arranged at the bottom of the kiln. According to the method disclosed by the invention, the oxidation rate is as high as 98%, the clinker extraction rate is as high as 99.97%, and the chromium yield is 97.96%.

The invention discloses a method for preparing phosphogypsum whiskers by secondary crystallization. The method comprises the steps of weighing dried phosphogypsum, adding a sulfuric acid solution, performing stirring reaction in a water bath, filtering when being hot, abandoning insoluble substances, cooling filtrate at room temperature for crystallization, performing suction filtration, and then retaining a filter cake; adding the sulfuric acid solution and a crystallization promoting agent, namely magnesium salt, performing stirring reaction in the water bath, naturally cooling the solution in the water bath for crystallization, performing suction filtration to obtain the whiskers, washing till neutrality and drying. The crystallization promoting agent is not used in primary crystallization in the method disclosed by the invention, the solid-liquid ratio of raw materials has a good effect, the reaction temperature and the stirring rotational speed are reasonably designed, the secondary crystallization method is created, the problems of short length-diameter ratio, low yield, difficulty in production under non-high pressure conditions and difficulty in succeeding without pretreatment of the phosphogypsum whiskers in the prior art are solved, the problems of phosphorus residue and the like can be solved by recycling a solvent, and the sustained cyclic production can be further realized. The length-diameter ratio of the whiskers produced by the method disclosed by the invention is more than 100, the whiteness is not less than 95%, and the product yield is improved by 10%-15%.

The invention discloses a method for recovering sodium sulfocyanate from coke-oven gas wastewater that is desulfurized and decyanated through a sodium alkali method. Belonging to a pure physical separation technology, the method of the invention has no need for additional accessories to take part in a reaction and does not discharge any wastewater and waste material to the outside, thus really reaching the purposes of eliminating environmental pollution, utilizing waste materials, change waste materials into things of value and realizing circular economy. The method provided in the invention has the advantages of novel technology, simple process, low cost, advanced technique, and practical applicability.

The invention discloses a flower fertilizer, which is prepared by fermenting waste materials such as peel, vegetable leaves, bones, leftovers, tea leaf slag and medicament slag. The invention is characterized in that: the waste materials such as peel, vegetable leaves, bones, leftovers, tea leaf slag and medicament slag are filled in a container; after a certain amount of water and leaven is filled into the container, the container is sealed for 2 to 3 days; when the waste materials are fully fermented, thoroughly decomposed and turned into black liquid, a plurality parts of hydrogen peroxide are added for absorbing odor; and the slag are removed by filtering, and the filtrate is diluted by 100 folds by water, and the diluted product is filled into small bags. The flower fertilizer of the invention is prepared by taking waste materials as the main raw materials, has the advantages of low cost and convenience for making, has little peculiar smell and can contribute to environment protection after being promoted widely.

The invention relates to an ammonia circulative preparation method for cobaltous oxalate. In the current commonest liquid phase precipitation method, because ammonium salt is introduced in the reaction process and the amount of oxalic acid is excessive during the reaction, impurities like ammonia nitrogen and oxalic acid root in synthesized waste water are required for processing. According to the invention, cobalt liquid is taken as a raw material, an oxalic acid solution is used for absorbing ammonia gas to prepare an ammonium oxalate solution which can be taken as an auxiliary material, cobalt liquid and the ammonium oxalate solution are added in a reaction vessel for synthesizing to obtain cobaltous oxalate pulp, the cobaltous oxalate pulp is filtered and washed, and dried to obtain the cobaltous oxalate product; simultaneously, waste water after filtering and washing is carried out pH regulation, ammonia molecule is separated from waste water by using an air stripping method, the oxalic acid solution is absorbed to be the ammonium oxalate solution for realizing the ammonia circulative utilization. The preparation method of the invention has the advantages that ammonia circulative utilization is realized, the waste water treatment avoids the introduction of ammonium salt and ammonia nitrogen, the production cost is reduced and the circular economy is realized.

The invention provides a reclamation method of used sodium silicate sand. The reclamation method comprises the following steps of: placing the used sodium silicate sand which is well crushed and screened into a closed or semi-closed container, introducing high-temperature water vapor at the temperature of 100 DEG C and above into the container for steaming and showering the used sodium silicate sand, steaming and showering for above 15 minutes, filtering out treatment fluid generated by steaming and showering from the bottom of the container, then taking the sodium silicate sand out of the container, and drying to get reclaimed sodium silicate sand. According to the reclamation method disclosed by the invention, sodium oxide in the used sodium silicate sand can be effectively removed so that the content of the sodium oxide is lower than 0.25%; and furthermore, a gel film in the sand can be effectively removed and the film removal rate can be up to above 90%. The performances of the reclaimed sodium silicate sand approach and even exceed those of new sand, so that the reclaimed sodium silicate sand can completely meet the using requirements of cast-molding. Moreover, the water consumption in the treatment process is very low, which is only 1 / 10-1 / 5 of the quantity of the treated sand, and the treatment fluid can also be comprehensively utilized, so that the reclamation method has the advantages of resource conservation, greenness and environmental protection, and is further conductive to realizing cyclic economy.

The invention relates to a Pleurotus eryngii culture medium which is prepared from the following raw materials in parts by mass: 40-60 parts of bacterial dreg, 30-40 parts of corn cob, 10-15 parts of bran and 0.9-1.1 parts of lime. By using the bacterial dreg instead of wood dust and cottonseed hull, the bacterial dreg is recycled, thereby enhancing the bioavailability of the effective constituents in the bacterial dreg; and thus, the invention solves the problem of raw material resources, effectively utilizes the agricultural leftovers, changes wastes into valuable substances and lowers the raw material cost and transportation expenses, thereby lowering the production cost of the Pleurotus eryngii and having favorable economical and ecological effects.