410 results about "Iron content" patented technology

According to the technical scheme, the efficient hot-dip galvanizing method based on the zinc liquid purification technology comprises the following steps of incoming material inspection, degreasing, acid pickling, rinsing, plating assisting, drying, hot-dip galvanizing, zinc draining and cooling, and the hot-dip galvanizing process is dynamically matched with electromagnetic stirring strength through gradual temperature control; based on a temperature-iron content response curve, parameters of all procedures are accurately controlled, temperature dynamic adjustment is achieved, collaborative optimization of the zinc liquid purification and slag salvaging process is achieved, and the method has the advantages that zinc slag is reduced, the coating uniformity is improved, and energy consumption is reduced.

The invention relates to a method for driving impurity iron to enrich and purify aluminum alloy return scrap and a product, the aluminum alloy return scrap is placed in a crucible, is heated in a resistance furnace and is subjected to heat preservation for a period of time, so that the return scrap is fully molten, and a melt is obtained; continuously preserving the heat of the melt, connecting two parallel electrodes with a pulse power supply, vertically inserting the two parallel electrodes into the melt, and preheating for a period of time; setting a first pulse voltage, a first pulse current and a first pulse frequency according to the impurity iron content of the aluminum alloy return scrap; second pulse voltage, second pulse current and second pulse frequency are set according to different heat preservation temperatures during melt electric pulse treatment, and electric pulse treatment is applied to the melt for a period of time in the heat preservation stage; and closing the resistance furnace and the pulse power supply after treatment, and cooling the melt along with the furnace to obtain a sample. The method effectively solves the problem of malignant accumulation of impurity iron elements in the aluminum alloy resource recycling process. The method is short in treatment time and high in iron removal efficiency, and the production cost can be greatly reduced.

The invention discloses a method and a system for measuring flow and iron content of fine iron ore pulp. The method comprises the following steps of: sleeving two detection coils with the same parameters on a transportation pipeline of iron fine powder ore pulp in a front-and-back spaced manner, connecting the two detection coils into a detection module, and acquiring two similar detection signals with time delay of the two detection coils when the detection signals flow through the iron fine powder ore pulp by using the detection module; and measuring and detecting the flow and the iron content by utilizing the property that the iron concentrate pulp contains ferromagnetic substances in the two detection signals. According to the invention, the volume flow rate of the iron fine powder ore pulp in the pipeline transportation process and the content of iron elements in the ore pulp can be detected in real time, the iron fine powder ore pulp can be monitored in the transportation process, control, distribution and settlement are convenient, and the iron content of the iron fine powder ore pulp can be known in real time, so that the iron content of the iron fine powder ore pulp can be known approximately.

The present invention relates to the technical field of test and detection, and particularly to an on-line measurement method and device for total iron in power station water vapor. A catalytic reagent is added to the water sample to be measured and acts through an ultraviolet light oxidizer, so as to completely convert the colloidal iron in the water sample into ferric ions. The dissolution and conversion of the colloidal iron are completed without adding acid throughout the process. Since no acid is added during the process of converting the whole colloidal iron into dissolved iron, only a chromogenic reagent needs to be added to accurately measure the total iron content in the water sample, and it is also easier to realize the on-line measurement of total iron in the water sample. When the total iron content in the water sample is less than 10 μg / L, the water sample enters the concentration system for concentration and then optical measurement, so that the low-concentration total iron in the water sample can also be accurately measured. This measurement method can automatically measure the total content in the water sample on-line, avoid manual sampling and detection, can monitor the total iron in the water sample in real time, and has a lower detection limit and more accurate detection results, which is beneficial to the adjustment of the water condition during the start-up and shutdown stages of the power station.

The invention discloses a method for removing iron impurities in regenerated aluminum alloy, and belongs to the field of non-ferrous metal regeneration, recovery and impurity removal. The method comprises the following steps: weighing an iron removal flux (25-45 wt.% of boron-containing potassium fluoride, 20-30 wt.% of sodium chloride and 20-35 wt.% of potassium chloride) according to the mass percentage, stirring, mixing and drying; according to the method, the aluminum scrap is put into the smelting furnace to be smelted, then the iron removal flux and the permanganate catalyst are added into the aluminum scrap melt, stirring and standing are carried out, the aluminum melt with the iron impurity element removed is obtained, the method does not affect the aluminum obtaining rate, meanwhile, the iron content is remarkably reduced, and the method is applied to aluminum ingots obtained through green regeneration smelting of the aluminum scrap and has the beneficial effects that the cost is low; the environment is not damaged and the steps are simple.

The present invention relates to the technical field of steel slag solid waste utilization, and in particular to a method for selective extraction of calcium and secondary magnetic separation of iron from steel slag, comprising the following steps: adding a leaching agent into steel slag, controlling the leaching temperature to be 95-125℃ and the pH of a leaching system to 5.5-8, and continuously leaching calcium for 0.5-2 h; in the process of leaching the calcium or after the leaching of the calcium is finished, adding an oxidizing agent into a reaction system, and oxidizing part of the original non-magnetic ferrous oxide in the steel slag into magnetic ferroferric oxide; and performing magnetic separation on residues obtained after leaching to obtain magnetically separated powder having a total iron content of greater than 40% and tailing powder having an iron oxide content of greater than 40%. According to the method, calcium in the steel slag can be efficiently and selectively extracted, and a steel slag ore phase can be changed while the calcium is extracted, so that most of iron in the residues obtained after leaching can be enriched by magnetic separation again, thereby realizing grading and efficient utilization of calcium and iron elements in the steel slag, and improving the recycling rate of the iron.

A golf club head has a loft no less than 38°. The golf club head also comprises a material having a material composition that includes an Iron content that by weight is highest of all constituents. The material composition also has a Chromium content no less than 10.5% by weight and a Nickel content no greater than 0.5% by weight.

The invention provides a resource utilization method of iron-aluminum-chromium waste acid, and belongs to the field of waste acid resource treatment. According to the hydrochloric acid type iron-aluminum-chromium waste acid, firstly, high-valence metal in the waste acid is reduced through iron powder, the acidity of a system is reduced, and the iron content is increased; secondly, high-efficiency separation of iron, aluminum and chromium is realized by accurately controlling the sodium phosphate amount, the pH value, the reaction temperature and the stirring rotating speed; and then, oxidizing an iron solution obtained by solid-liquid separation to prepare ferric chloride, and carrying out hydrothermal crystallization on aluminum phosphate and chromium phosphate precipitates to prepare chromium-containing aluminum phosphate which can be used as a catalyst. The method realizes thorough step-by-step separation of metals in the iron-chromium-aluminum hydrochloric acid type waste acid, realizes resource utilization, is free of waste gas and waste residues in the process, meets the green and environment-friendly requirements, and has remarkable environmental and social benefits.

The low-grade magnetite magnetic separation process comprises the following steps that 1, raw ore is crushed, the raw ore is magnetite with the magnetic iron content not higher than 10%, raw ore particles are obtained after the raw ore is crushed, and the particle size range of the raw ore particles is 1-2.5 cm; 2, primary strong magnetic separation is conducted on the raw ore particles, middlings and tailings I are obtained, the iron grade of the middlings is 14%-22%, and the iron grade of the tailings is 3%-5%; 3, the middlings are sequentially subjected to first-stage ore grinding, second-stage magnetic separation, second-stage ore grinding and third-stage magnetic separation, and iron ore concentrate and tailings III are obtained; and the tailings I are sequentially subjected to tailings grain decomposition and tailings magnetic separation to obtain tailings II and tailings III, and the tailings II are returned to secondary grinding again. According to the method, the tailings I are subjected to grain dissolving-regrinding optimization, the tailings I are subjected to secondary dissociation through a high-pressure roller mill or a dry crusher, micro-fine particle magnetic minerals are released, after magnetic separation is conducted, the tailings II are returned to the original process for further grain dissolving and magnetic separation, qualified iron ore concentrate products are obtained, and resource waste is avoided.

The invention relates to the technical field of selective impurity removal of valuable elements in acid solutions, in particular to a method for selective iron removal of rare earth pickle liquor. The method comprises the following specific steps: firstly, taking pickle liquor generated in an industrial production process, adding a first medicament, and stirring for pretreatment; adding a second medicament into the pretreated solution, and stirring to selectively remove iron; finally, a coagulant is added for solid-liquid separation, and supernate and iron-containing sediment are obtained. The total iron content in the supernate is lower than 5.0 mg / L, so that the production requirements of enterprises are met. The method has the advantages of simple and easy process, low equipment requirement, convenience in operation, wide application range and the like, and has good social benefits and economic values.

The invention discloses a method for preparing high-purity quartz and recovering an iron element based on high-silicon tailings, and belongs to the technical field of comprehensive utilization of resources and preparation of high-purity quartz. According to the method, high-silicon tailings are sequentially subjected to mineral dissociation, low-magnetic-field roughing, high-magnetic-field scavenging, flotation and ultrasonic acid leaching treatment, and refined quartz is obtained; and carrying out multi-stage gradient chloridizing roasting and hot-pressing acid leaching treatment on the refined quartz of which the gas-liquid inclusion index and transparency meet the requirements to finally prepare the high-purity quartz of which the SiO2 purity is greater than or equal to 99.995%. In addition, for strong magnetic minerals generated in the magnetic separation process, the iron content of the strong magnetic minerals reaches the standard, the strong magnetic minerals react with the acid leaching filtrate under the ultrasonic strengthening condition to leach iron ions, and iron-rich filtrate is subjected to an iron precipitation reaction to generate iron carbonyl. The method provided by the invention not only provides a reliable judgment basis and a complete technical route for preparing high-purity quartz from the high-silicon tailings, but also opens up a new way for resource utilization of the tailings, and has remarkable industrial application value and environmental benefits.

The invention relates to the technical field of hafnium oxide preparation, in particular to a method for preparing hafnium oxide with ultralow iron content, which comprises the following steps: based on N235 extraction separation in a hydrochloric acid system, crushing hafnium oxide raw stone, performing coarse grinding to obtain hafnium oxide powder, then sequentially performing alkali fusion decomposition treatment and acid leaching impurity removal treatment to obtain a zirconium-hafnium mixed solution, and then performing vacuum drying on the zirconium-hafnium mixed solution to obtain the hafnium oxide with ultralow iron content. The preparation method comprises the following steps: taking hafnium as a raw material, carrying out extraction and back extraction to obtain a hafnium-enriched solution, treating the hafnium-enriched solution with ion exchange resin to obtain a high-purity hafnium solution, finally adding saturated ammonia water, filtering and washing the obtained precipitate, drying, and firing to obtain the hafnium oxide with ultralow iron content. According to the invention, while zirconium and hafnium separation is realized, a small amount of contained metal cations, especially iron ions, are fully removed, and the iron content is reduced, so that hafnium oxide with ultralow iron content is obtained.

The invention relates to the field of metal materials, in particular to a high-strength and high-toughness die-casting aluminum alloy and a preparation method thereof.The high-strength and high-toughness die-casting aluminum alloy comprises, by weight, 4.0%-4.5% of magnesium, 1.8%-2.6% of silicon, 0.5%-2.0% of iron, 0.3%-1.2% of manganese, 0.3%-1.2% of chromium, 0.5%-3.0% of zinc and the balance aluminum and inevitable impurities; the sum of the weight percentages of manganese and chromium is greater than or equal to the weight percentage of iron. The problems that an existing die-casting aluminum magnesium alloy is low in strength, difficult to regenerate and high in process cost can be solved, and certain strength and toughness can still be guaranteed while the high iron content is achieved.

The invention discloses a method for preparing iron oxide and calcium chloride by electrochemically recovering iron-containing waste hydrochloric acid, and belongs to the technical field of waste acid treatment. The method comprises the following steps: S1, respectively putting a cathode and an anode at two ends of an electrolytic cell, putting a diaphragm to separate the cathode and the anode, filtering the iron-containing waste hydrochloric acid, removing suspended matters and solid residues, and introducing the iron-containing waste hydrochloric acid into the electrolytic cell; s2, measuring the content of iron element and the content of free acid in the iron-containing waste hydrochloric acid, and adding a neutralizing agent to neutralize redundant free acid; s3, applying voltage between the cathode and the anode according to the content of the iron element, performing electrolytic reaction to generate an oxidation intermediate, and oxidizing the iron element by using the oxidation intermediate to obtain a precipitate iron oxide and a calcium chloride solution; and S4, adding a proper amount of water into the reaction solution for dilution, filtering to obtain iron oxide, and concentrating the filtrate to obtain calcium chloride. According to the method, the oxidation intermediate generated by waste hydrochloric acid electrolysis is used as the oxidizing agent, the ferrous ions in the waste hydrochloric acid are selectively oxidized, other oxidizing agents do not need to be additionally added, new impurities cannot be generated in the oxidation process, the treatment time is short, the product is controllable, and remarkable economic benefits and social benefits are achieved.

The invention discloses a smelting method for low-alkalinity and low-total-iron converter dephosphorization, and belongs to the technical field of steel smelting. Ore, lime, dolomite and light-burned dolomite are added for slagging in the early stage and the middle stage of converter smelting; after TSC measurement in the later period of smelting, high-lance-position oxygen supply blowing is adopted, ore is added in the period to promote slagging and dephosphorization, then low-lance-position oxygen supply blowing is adopted, DRI is added into the converter in the period, bottom blowing is reasonably controlled to reduce the total iron content of the steel slag, generation of MgO solid particles and C2S-C3P solid solution is promoted, and therefore the purposes of low alkalinity and low total iron dephosphorization at the end point of the converter are achieved. The alkalinity R of the final slag of the converter is controlled to be 2.4-2.8, the content of MgO is controlled to be 8.0-11.0%, the content of total iron is controlled to be 10.0-15.0%, and the content of P in the final molten steel is smaller than or equal to 0.02 wt%.

The invention relates to the technical field of blast furnace ironmaking furnace temperature control, and discloses a blast furnace temperature grading diagnosis regulation and control method, device and equipment, and the method comprises the following steps: obtaining current operation data of a blast furnace, and utilizing a furnace temperature trend prediction model to obtain predicted molten iron silicon content of the blast furnace; the current molten iron silicon content is obtained, and the furnace temperature trend is determined according to the predicted molten iron silicon content and the current molten iron silicon content; determining a furnace temperature change level according to the furnace temperature trend and a preset furnace temperature change grading table; acquiring current production data, and determining current furnace condition characterization of the blast furnace according to the current production data; and according to the furnace temperature change level and the current furnace condition characterization, the adjusting quantity of the preset adjusting and controlling parameters is determined through a furnace temperature adjusting and controlling model. According to the method, the accurate predicted furnace temperature is obtained by predicting the silicon content of the molten iron, the furnace temperature change trend and the furnace condition characterization are analyzed to determine the furnace temperature change reason, an effective regulation and control means is adopted, accurate regulation and control of the furnace temperature of the blast furnace are achieved, huge fluctuation of the furnace temperature is avoided, and long-term stable operation of the blast furnace is guaranteed.

The invention belongs to the technical field of hematite ore mining, and particularly discloses a hematite ore particle strong magnetic separation device which comprises a screening cylinder, a hopper is fixed to the top of the screening cylinder, the top of the screening cylinder is closed, and a conical material guide block is arranged at the position, close to the bottom edge, in the screening cylinder. A plurality of supporting rods are fixed to the outer surface of the conical material guide block in the circumferential direction at equal intervals, one ends of the multiple supporting rods are correspondingly fixed to the inner wall of the screening barrel, and an electromagnetic screening device for screening iron ore particles is arranged on the conical material guide block. A supply device for conveying iron ore particles is arranged at the position, close to the top edge, in the screening barrel, and a plurality of auxiliary devices are arranged in the conical material guide block; according to the hematite detritus collecting device, by arranging the supply device, the electromagnetic screening device and the auxiliary device, crushed hematite detritus with the high iron content can be collected, and detritus blocks or hematite detritus blocks with the extremely low iron content can be screened out.

The invention belongs to but not limited to the technical field of metal impurity removal, and particularly relates to a method and system for removing iron elements in secondary aluminum based on a centrifugal casting method.The method comprises the steps that S1, raw materials are prepared, specifically, secondary aluminum raw materials are collected, classified and treated, impurities and oil stains in the secondary aluminum raw materials are removed, and the quality of the raw materials is ensured; s2, preheating treatment is conducted, specifically, the secondary aluminum raw material is heated to a certain temperature to reach a proper casting temperature; s3, centrifugal casting is conducted, specifically, centrifugal casting equipment is adopted, the preheated secondary aluminum raw material is injected into a rotating mold, and iron elements in molten aluminum are gathered towards the wall face of the mold under the action of centrifugal force; s4, separation and collection: after the molten aluminum is cooled and solidified, the casting is taken out of the mold, an iron element enrichment layer on the surface of the casting is removed through a mechanical or chemical method, and secondary aluminum with the low iron content is obtained; and S5, follow-up treatment is conducted, specifically, the obtained low-iron-content secondary aluminum is further treated, including refining and alloying, so that different application requirements are met.

The invention provides a functional aggregate, a preparation method thereof and a self-purification asphalt pavement material. The preparation method of the functional aggregate comprises the following steps: screening residual mud and residue soil, crushing and screening to obtain a raw material, or mixing low-iron-content residue soil and red mud to prepare the raw material; the preparation method comprises the following steps: heating raw materials to 400-550 DEG C, introducing CO2, carrying out heat preservation for 40-120 minutes, then heating to 750-850 DEG C, and carrying out heat preservation for 40-120 minutes, so as to obtain calcined aggregate; soaking the mixed material in a mixed solution containing 0.1-1mol / L FeCl3 for more than 10 hours, and then carrying out hydrothermal reaction at 100-150 DEG C for 4-8 hours to obtain aggregate; and dipping the aggregate in a bacterial liquid containing denitrifying bacteria, petroleum hydrocarbon degrading bacteria and a curing agent, and obtaining the functional aggregate by adopting a vacuum negative pressure dipping method. The material formed by compounding the functional aggregate and the asphalt modifier has the functions of adsorption, catalytic oxidation and biodegradation.

A preparation method of the steel slag-based binder comprises the following steps: crushing converter steel slag, grinding to 150 meshes or below to obtain converter steel slag fine powder, removing iron, continuously grinding to 300-350 meshes, and removing iron again until the metal iron content is less than or equal to 0.5 wt% to obtain active steel slag powder; fly ash and water are mixed and then settled, bottom sediment is taken and dried till the water content is smaller than or equal to 3 wt%, and pretreated fly ash is obtained; and mixing the active steel slag powder, the pretreated fly ash, pyrophyllite and wollastonite according to a certain ratio, and uniformly grinding to obtain the steel slag-based binder for preparing the micro-electrolysis iron-carbon spheres. The method not only solves the problem of recycling of steel slag resources, but also can prepare the iron-carbon micro-electrolysis filler with low production cost, so that the cost is remarkably reduced.

The invention relates to the technical field of agriculture, in particular to an iron-rich yield-increasing foliar fertilizer for rice as well as a preparation method and an application method of the iron-rich yield-increasing foliar fertilizer. According to the specific technical scheme, the iron-rich yield-increasing leaf fertilizer for the rice is prepared from, by mass, 15%-25% of porous chitosan, 20%-30% of L-malic acid and 45%-55% of ferrous sulfate. The technical problem that in the prior art, the cadmium content of brown rice cannot be reduced while the iron content cannot be increased through a leaf fertilizer is solved.

The invention relates to the technical field of iron content detection, in particular to an iron ore total iron content detection method and system based on spectral analysis, and the method comprises the steps that after spectral data of iron ore are obtained, an improved envelope line method is adopted for preprocessing the spectral data, determining the local maximum value point of the spectral data by adopting a sliding window method, specifically, determining the size of a window for searching the local maximum value point of the spectral data by adopting the sliding window method according to the number of data points of a maximum characteristic peak of a spectral curve of the spectral data, so that the robustness of determining the local maximum value point of the spectral data is improved; when the envelope line node is determined, not only is the local maximum value considered, but also the intersection point of the fitting curve of the spectrum curve is considered, and the feature points in the two aspects are taken as the envelope line node, so that the envelope line node is determined more accurately, and the characteristics of the spectrum curve can be reflected better.

The invention discloses a high-yield integrated production method for cigar wrappers. This method builds a “four in one” production facility system that integrates seedling cultivation, transplanting, drying, and fermentation processes of cigar wrapper tobacco leaves. The system has a light intensity of 75-160 umol / (m2·s), a temperature of 25±5° C. and a relative air humidity of 75%±10%; when transplanting tobacco seedlings, using a nutrient solution, which is a high iron boron nutrient solution with an iron content of 0.3-0.7 mM calculated as Fe and a boron content of 9.5-13.0 mg / L calculated as boric acid. The invention achieves a cigar shell yield of over 65%, a 40% reduction in production facility investment, and a 20% reduction in labor force by accurately regulating the production environment and the supply of growth factors such as nutrients and light.

A metal powder for additive manufacturing including, in wt %, Ni 9.0-12.0, Cr 2.0-4.5, Mo 3.5-4.5 and Ti 0.1-1.0; and, if present, Si up to 0.5, Mn up to 0.5, Al up to 0.1, Co up to 0.1, N up to 0.05 and / or C up to 0.07; the balance being Fe and usual impurities. A use of the metal powder for additive manufacturing is also provided, as well as a process for producing an object by additive manufacturing, including building an object by iteratively melting particles of the metal powder and solidifying the melt, and subsequently aging the built object without any preceding solution annealing thereof.

The invention relates to a high-iron-content aluminum alloy welding wire and a preparation method and application thereof, and belongs to the technical field of welding. The aluminum alloy welding wire with the high iron content is composed of, by mass, 1.0%-3.0% of Si, 0.8%-3.5% of Fe, 1.0%-3.0% of Mn, 0.2%-1.5% of Cr, 0.2%-1.5% of V and the balance Al and other inevitable impurities. The mass ratio of Mn to Fe is 0.85 to 1.0; the mass ratio of Cr to Mn is 0.25 to 0.4; the mass ratio of (Mn + Cr) / Fe is 1.1-1.3; the mass ratio of V / (Mn + Cr) is 0.2-0.3; and the mass ratio of Si to (Fe + Mn + Cr + V) is 0.35-0.5. And the comprehensive performance of the welding seam is improved through an organization regulation mechanism.

The invention relates to the technical field of metal casting, and discloses a smelting and casting method of a high-toughness regenerated aluminum alloy, which comprises the following steps: measuring the iron content of a regenerated aluminum melt, regulating and controlling the manganese-iron ratio, heating the melt to 750-790 DEG C, and carrying out overheating treatment to eliminate a hereditary core; cooling to 630-645 DEG C, applying a mechanical shear flow field with the average shear rate not lower than 60s <-1 > in the interval, stripping a diffusion boundary layer on the surface of the iron-rich phase crystal nucleus by utilizing fluid drag force, breaking dendritic crystals, and separating out in a polyhedral or spherical manner; according to the method, through active intervention of a critical shear flow field, the problem of needle-like growth of an iron-rich phase caused by solute diffusion blocking in a traditional technology is solved, in-situ generation of the harmless iron-rich phase in the high-iron-content secondary aluminum is achieved, the obdurability of a die casting is improved, and dependence on the purity of raw materials is reduced.

The invention discloses a method for reducing the content of iron in rare earth chloride, which comprises the following steps: step 1, adding alkali slurry into heavy sand slurry containing ferrous ions to adjust the pH value to 1-2, then adding an oxidizing agent, and reacting for 2-3 hours at the temperature of 30-45 DEG C to oxidize the ferrous ions into ferric ions to obtain first rare earth slurry, the concentration of ferrous ions is 0.1-0.2 g / L; 2, the pH value of the first rare earth slurry is adjusted to 3.8-4.2, a reaction is conducted for 1.5-2.5 h at the temperature of 62-68 DEG C, so that ferric ions form precipitates, and second rare earth slurry is obtained; 3, carrying out solid-liquid separation on the second rare earth slurry to obtain an optimal solution filtrate and a filter cake; and step 4, performing removal, solid-liquid separation, evaporation and concentration on the optimal solution filtrate to obtain a rare earth chloride product with the iron content lower than 0.05%. The invention aims to introduce hydrogen peroxide in the thorium neutralization and deposition stage to reduce the accumulation of iron impurities in the circulation process.

The invention discloses a method for preparing nano calcium carbonate by efficiently removing iron impurities in nano calcium carbonate raw material ore, and belongs to the technical field of nano material preparation. The method comprises the steps of raw material pretreatment, digestion treatment, size mixing treatment, carbonization treatment, surface treatment and drying, in the size mixing treatment process, a whitening agent Na2SO3 is adopted for removing iron in raw material ore, Na2SO3 serves as a reducing agent, Fe < 3 + > is reduced into Fe < 2 + >, a proper amount of whitening auxiliary such as DTPA or triethanolamine forms colorless water-containing iron chelate ions with iron ions, and the iron chelate ions are subjected to surface treatment. And through a synergistic system of the whitening agent and the whitening auxiliary agent, efficient removal of iron is realized. The whiteness of the prepared nano calcium carbonate reaches up to 97.2%, the nano calcium carbonate has the remarkable advantages of being efficient, environmentally friendly, economical and the like, the iron content in the nano calcium carbonate can be remarkably reduced, the purity and whiteness of the product are effectively improved, and the high requirement of the high-end application field for the quality of the nano calcium carbonate is met. Meanwhile, the method is simple and convenient to operate and easy to industrially apply, and has wide market prospects and popularization value.

This invention provides a coal mine wastewater retreatment device, comprising a treatment tank with two sets of symmetrically distributed support legs fixed at the bottom. A filter screen is installed inside the treatment tank. An inlet pipe is connected to the top of one side of the treatment tank, and an outlet pipe is connected to the bottom of the other side. An adsorption mechanism for removing iron-containing impurities is installed at the top of the treatment tank, comprising a magnetic column with two symmetrically distributed circular plates fixed to its outer side. The coal mine wastewater retreatment device provided by this invention solves the problem that existing treatment devices' filters are limited to filtering coal slag and are not suitable for cleaning iron-containing impurities in coal mine wastewater. This results in iron-containing impurities mixing inside the coal mine wastewater and entering the environment along with the wastewater discharge, leading to high iron content in the environmental water and making the water prone to turbidity due to reaction with oxygen in the air.

The present invention relates to the field of environmental protection technology, and in particular to a manipulator for steel slag processing, a steel slag processing system and method based on image processing, used in steel slag processing. The manipulator includes a base, a first moving hand provided on the base, a second moving hand and a motion control mechanism; the first moving hand includes a plurality of evenly distributed first fingers, the second moving hand includes a plurality of evenly distributed second fingers, and the first fingers and the second fingers are arranged opposite to each other; the motion control mechanism controls the movement of the first moving hand and the second moving hand between a first state and a second state. Through a special manipulator structure, scrap steel with a high iron content is grabbed or sieved and fished out from the granulated steel slag, and then combined with image processing technology, the scrap steel is grabbed in a confined space, and the scrap steel is sorted out while avoiding environmental pollution.