904 results about "Hematite" patented technology

The invention discloses a benefication method for recovering specularite. The method comprises the processes of primary grinding, grading, primary low intensity magnetic separation, and tailings discarding by primary high intensity magnetic separation; rough concentrate pre-classification by the primary low intensity magnetic separation and the primary high intensity magnetic separation, secondary grinding, secondary low intensity magnetic separation to obtain concentrates, secondary high intensity magnetic separation to obtain concentrates; and selective flocculation desliming secondary conducted on high intensity magnetic separation tailings (middlings), and anionic reverse flotation. The method further comprises the step of arranging a cylindrical slag separating sieve before the primary high intensity magnetic separation. With the advantages that the iron concentrate grade and the iron recovery are high, the loss of granular iron minerals is low, the mineral process flow is short, concentrates and tailings can be obtained in advance and the energy consumption of the benefication is low, the invention can be used not only for selecting specularite ores, but also for selecting weakly magnetic iron minerals, such as hematite, goethite, siderite, limonite, and the like.

The invention belongs to the fields of chemical engineering and metallurgy and in particular relates to a process system which adopts a circulating fluid bed to carry out magnetization roasting on limonite, siderite, sedimentary hematite and other refractory iron ore powder bodies. The process system adopts a high-efficiency low-resistance reactor of the circulating fluid bed to carry out the magnetizing roasting to the iron ore powder body; firstly, roasted tail gas in a combustion chamber releases latent heat of unreacted reducing gas through combustion; secondly, the roasted tail gas exchanges heat with the cold iron ore powder body through a multilevel cyclone preheater to reclaim heat; and finally a fluidizing cooler is adopted to reclaim sensible heat of high-temperature roasting ore. The process system has the advantages of high magnetizing roasting efficiency and full heat reclaiming and utilization in the roasting process and the like, can reduce energy consumption of the refractory iron ore powder body in the process of magnetizing roasting and improve the economical efficiency of the refractory iron ore in the process of magnetizing roasting.

The preparation method for a solvent-type iron ore composite aggregate comprises: ensuring the proper CaO and 2-4% MgO with weight o.5-2.0 in the first process; then coming the secondary time, wrapping one block layer evenly of CaCo3 powder, dolomite powder, hematite dried powder or acidic iron concentrate ore; then, baking as the acidic aggregate baking temperature and means to ensure the ore not bond. This invention overcomes bonding problem with low cost and little pollution, and improves blast furnace yield even meets the pH balance or desulfurization request.

The invention relates to a high phosphorus hematite-hematite-limonite magnetic roasting-extraction phosphorous reduction method, in particular applicable for an extraction phosphorous reduction method for the iron ores which mainly include the hematite-hematite and the limonite and accompany with magnetite, pyrrhotite, iron pyrites, etc. The method of the invention adopts magnetic roasting-wet extraction to reduce phosphorous; after carrying out modifying on high phosphorus iron ore, muriatic acid or vitriol is selected to carry out extraction phosphorous reduction on the iron concentrate obtained by a weak electromagnetic separator which not only can obtain the iron concentrate with an iron grade to be larger than 56 percent; simultaneously the content of the phosphorous in the iron concentrate is lower than 0.30 percent.

The present invention discloses a method for adopting the limonite and the siderite to produce iron powder and a reduction roaster. The material adopts the limonite and the siderite or the specularite, the hematite, and the sulphuric acid slag, the inclined rotary reduction roaster is used, the pressure of the furnace chamber is 250 to 350 Pa, under the deoxidizing atmosphere, the inert solid is rotated and moved to 650 to 900 DEG C from the low temperature, and is cooled and magnetized, and lastly become the iron powder through the dressing by magnetic separation. The present invention is adopted to produce the iron powder, the resources is rich and the production cost is low, and through the utilization of the powder metallurgy art, the iron content of the iron powder is controlled and the activation energy of the iron powder is reduced, and the chemical reaction ability is increased, thereby the output of iron powder is high, the quality is good, the iron powder is loose and porous, the specific surface is big, the apparent density is large, the manufacture cost of pellets sinter and steel smelting can be reduced greatly, and the iron powder can use directly to produce iron oxide red as well as H and N synthetic iron catalyst, or produce ultrapure iron powder.

A technique method for directly producing spongy iron by using high phosphorus oolitic hematite belongs to the iron making field, and is characterized in that the high phosphorus oolitic hematite is added with a dephosphorizing agent and then is subjected to direct metallization reducing roast by taking coal as a reducing agent, low intensity magnetic separation for raising iron and reducing phosphorus is carried out, thus obtaining the substance with more than 90 percent of iron metal and phosphorus less than 0.08 percent. The invention has the advantages as following: (1) the utilization rate of resource is high, thus shortening the process flow of making raw steel material from iron ore, avoiding from polluting environment in concentrated ore sintering, pelletizing and blast furnace ironmaking in other methods, and having obvious environmental benefits, energy-saving and consumption reduction effects; (2) the technique method is simpler than other methods, the iron raising process and phosphorus reducing process can be completed simultaneously; and (3) coal power with low cost is directly taken as the reducing agent instead of the expensive coke, thus saving the cost in coking process and avoiding from polluting environment; the varieties are simple, the source is rich, the discharging amount of pollutants in the method is less than that in other methods and the pollutants are easy to deal with.

The ore dressing process of oolitic high phosphorus hematite includes the following steps: roasting crushed oolitic high phosphorus hematite in 80-99 wt% with coal powder as reductant in 1-20 wt% inside a shaft furnace or rotary kiln at 700-1050 deg.c for 0.5-2.5 hr and sealed cooling to room temperature; crushing the roasted hematite, grinding and weak magnetic separation; regulating pH value of the coarse concentrate to 8-12, adding iron ore inhibitor sulfonated starch in 0.5-3.0 kg/ton, activator in 0.2-2.0kg/ton and collecting agent in 0.2-3.0kg/ton and final reverse floatation. The process converts the weak magnetic hematite into strong magnetic mineral, concentrates iron mineral via weak magnetic separation and eliminate P, Si and other impurities in reverse floatation, and can obtain iron concentrate with iron grade higher than 63 %, P content less than 0.15 %, and iron recovering rate over 75 %.

The invention discloses a magnetic-gravity combined ore dressing technology for hematite, comprising the following steps of: carrying out dry magnetic separation and jigging gravity separation to obtain blast furnace lump ore, throwing the tailings of the lump ore, carrying out first-stage ore grinding, weak magnetic separation, strong magnetic separation and centrifugal gravity separation on middlings, and carrying out second-stage ore grinding, weak magnetic separation, strong magnetic separation and centrifugal gravity separation. According to the technology, part of qualified blast furnace lump ore (the iron grade is large than 54%) can be obtained in advance, the massive tailings (the iron grade is less than 12%) can be thrown out, the quantity of the ball-milled ore (the middlings) can be greatly reduced, and the grinding and separation energy consumption can be greatly reduced. The massive tailings which are thrown out can replace the macadam and the stone to be taken as the building material, so that the comprehensive utilization of the bulk quantity of the tailings resource can be realized, and the technology is prominent in emission reduction effect; and the whole ore dressing technology is the magnetic-gravity combined ore dressing technological process, so that the flotation reagents can not be consumed, the technology is very friendly to the work environment and the neighboring environment, the environment can be protected, the pollution of the beneficiation reagent to the environment caused by the flotation work can be avoided, and the technology is particularly suitable for the ore dressing of the medium and high-grade (the iron grade is more than or equal to 38%) hematite.

The invention discloses a method for separating oolitic hematite, and the process of the method comprises discarding tailings of ores by intense magnetic separation through stage grinding and stage separation, and de-phosphorizing and increasing iron to the intense magnetic concentrated by reverse flotation. The intense magnetic separation is functioned of concentrating iron minerals and desliming, thereby preventing smile from influencing flotation. The highly-effective regulator is made from sodium carbonate, sodium silicate and sodium hydroxide, the collecting agent is a composite medicine made from hydroximic acid and alkyl sulfate, and the method for separating oolitic hematite is a key technology for the reverse flotation to further upgrade the concentrate of iron ore. The invention has the advantages of simple technological process, low energy consumption, low cost and good product index, and solves the defects in prior art.

The invention discloses an anaerobic biological oxidation water pollution remediation method with Fe3+ in hematite as an electron acceptor. According to the method, Fe3+ in hematite serves as the electron acceptor and is loaded with functional microbial florae, and reduction-state pollutants in water are subjected to oxidation removal in the anaerobic or anoxic environment, wherein functional microorganisms include Geobacter sulfurreducens and Shewanella spp.. The method is wide in application range, low in cost, ideal in effect and especially suitable for remediating polluted water with high remediation difficulty.

The present invention relates to a lean hematite stage grinding and high intensity magnetism, gravity separation, negative ion reverse flotation technique which includes the following steps of: feeding lean hematite for a first grinding after which a first classification is given; feeding effluence of the first classification under medium intensity magnetism and high intensity magnetism; feeding concentrates into a classification between coarse and fine grits and discarding ore tailings; after the coarse and fine grit classification, feeding the coarse grit products into a coarse snail and fine grit products to concentration; feeding the fine grits from the coarse snail into a fine snail, the fine grits of which are gravity separating fine grits; feeding tailings from the coarse and fine snails into a second classification, the effluence of which goes back to medium intensity magnetism; feeding concentrated underflows into a coarse flotation and discarding the effluents; feeding the fine grits from the coarse flotation into a fine flotation and the tailings into a first sweeping flotation; fine grits from the fine flotation being the fine grits of the flotation and returning the tailings back to the coarse flotation; returning the fine grits from the first sweeping flotation back to the coarse flotation and feeding the tailings into a second sweeping flotation; returning the fine grits from the second sweeping flotation back to the first sweeping flotation and feeding the tailings into a third sweeping flotation; returning the fine grits from the third sweeping flotation back to the second sweeping flotation and discarding the tailings. The technique reduces the work load of the preparation equipment and the cost of mineral separations.

The invention relates to a chloridizing segregation-low-intensity magnetic separation method for reducing phosphorus of a high phosphorus iron ore. A chloridizing segregation-low intensity magnetic separation process is adopted to realize iron increase and phosphorous reduction in the method. A chlorinating agent and a reducing agent coke are added to the high phosphorus iron ore and mixed evenly, then chloridizing segregation roasting is carried out in a roasting furnace; the roasted product is water quenched and ball milled, and then separated by a low-intensity magnetic field magnetic separator, thus being capable of obtaining an iron ore concentrate with the iron grade more than 80%, the iron recovery rate more than 85% and the phosphorous content less than 0.20%. The iron ore concentrate powder can be taken as a raw material for smelting pig iron after being pelletized. Additionally, with regard to high phosphorus iron ores which contain sulfur or contain sulfur and arsenic at the same time, such as hematite, hematite-limonite ore, oolitic hematite-limonite ore, hematite, siderite and the like, the product iron ore concentrate with the sulfur content less than 0.20% and the arsenic content less than 0.04% can also be obtained.

A method for making a ferritic stainless steel article having an oxidation resistant surface includes providing a ferritic stainless steel comprising aluminum, at least one rare earth metal and 16 to less than 30 weight percent chromium, wherein the total weight of rare earth metals is greater than 0.02 weight percent. At least one surface of the ferritic stainless steel is modified so that, when subjected to an oxidizing atmosphere at high temperature, the modified surface develops an electrically conductive, aluminum-rich, oxidation resistant oxide scale comprising chromium and iron and a having a hematite structure differing from Fe₂O₃, alpha Cr₂O₃ and alpha Al₂O₃. The modified surface may be provided, for example, by electrochemically modifying the surface, such as by electropolishing the surface.

The invention discloses a treatment method of oolitic hematite containing phosphorus and is characterized in that the treatment method sequentially comprising the steps of: (1) evenly mixing raw ore of oolitic hematite, an annexing agent and coal in proportion and then crushing; (2) conducting metallization reducing roasting on crushed ore in the step (1); (3) slowly cooling high temperature roasted products to 400-750 DEG C, then quickly cooling through water quenching, and conducting water quenching roasted product ball milling; (4) conducting magnetic selection after the ball milling to obtain iron powder and tailings; and (5) melting the iron powder obtained in the step (4) to obtain high-quality molten iron with phosphorus less than 0.01%. The raw ore in the treatment method does no need fine grinding, and thickness of the raw ore can be directly crushed to be -5mm, and the raw ore does no need pelletizing, only needs even mixing with the annexing agent and the coal, greatly saves ore grinding and pelletizing cost, special-grade high-quality molten iron with the phosphorus less than 0.01% is produced by melting, the molten iron can serve as a raw material for producing high-quality steel, and a product production value is high.

The invention belongs to the technical field of preparing low grade hematite ore, in particular to a process for processing a low grade hematite ore. The process comprises the following steps: the ore is ground until monomer separation and then coarse and fine classification is carried out on pulp; coarse grain pulp is subject to reselecting, ferromagnetism and sieving to obtain a part of the concentrate; the fine grain pulp is conveyed to a mixing tank for separating sample, and then is conveyed to a second mixing tank to be mixed with medicine for size mixing; the mixture is pumped to a rough flotation column; the under flows of the rough flotation column is fed to a cleaning flotation column, the under flow of the cleaning flotation column is the ultimate iron ore concentrate; foam of the rough flotation column is conveyed to an one-stage scavenging flotation column by a pump; the under flow of the one-stage scavenging flotation column and the foam of the cleaning flotation column are mixed and return to the rough flotation column, and products of the one-stage scavenging flotation column are final tailings. The process has the beneficial effects of smaller occupation area by replacing a flotation machine with the flotation column, can recycle fine-grade valuable mineral effectively, improve the ultimate concentrate grade, provides reference significance for the mineral separation of the ore of the same type in China, and has obvious economic benefits and social benefits.

The invention provides a method for recovering copper, iron and silicon from copper smelting slag. The method comprises the following steps: (a) adopting oxygen to oxidize hot copper smelting slag to obtain mixed slag charge, wherein the temperature of the hot copper smelting slag is 1000-1350DEG C, and the mixed slag charge comprises hematite, copper oxide ore and quartz mine, and carrying out slow cooling processing on the mixed slag charge; (b) recovering the hematite from the mixed slag charge subjected to the slow cooling processing in the step (a) through flotation and magnetic separation, receiving a copper-contained product through activation flotation or leaching, and finally filtering tailings subjected to hematite recovery and the copper-contained product to obtain a silicon-contained product. The method provided by the invention has the advantages of short flow, simple technology, easiness in realization and control, wide use range, high practicality and the like and basically meets copper smelting slag resourceful processing requirements of the copper smelting industry. In addition, the method for recovering the copper, the iron and the silicon from the copper smelting slag, which is provided by the invention, does not generate secondary wastes, is free from pollution and has little energy input.

The invention discloses a method for carrying out direct reduction, sorting, agglomeration, smelting and ironmaking on ore and coal. Firstly, certain amount of the ore, the coal and a solvent are mixed, are placed in a rotary hearth furnace and are heated to the temperature of between 1,100 and 1,350 DEG C, are kept at the temperature for 15 to 40 minutes and are directly reduced to obtain a reduced iron material with metallizing rate of between 80 and 92 percent; the reduced iron material at high temperature of between 800 and 1,100 DEG C is directly transported into water, is cooled and is subjected to fine grinding and sorting; and the iron material after the fine grinding and sorting is subjected to drying and agglomeration by high-temperature oxygen-lost exhaust gas and finally is transported into a submerged arc furnace or other smelting equipment for carrying out slag-iron separation and molten iron production. The method has a simple process, short flow and high efficiency, needs no coke and is suitable for low-grade ore and non-blast furnace ore which is difficult to be used by the prior blast furnaces, such as oolitic hematite, ultrafine particle hematite, limonite, siderite and the like.

The invention relates to a technique for processing high-iron-carbonate mixed ore. The technique for processing the high-iron-carbonate mixed ore is characterized in that the stage grinding technique and the weak magnetic-strong magnetic-centrifugal machine technique are adopted, and separate grinding and separate screening are carried out on the high-iron-carbonate mixed ore. The technique for processing the high-iron-carbonate mixed ore has the advantages that the weak magnetic technique, the strong magnetic technique and the centrifugal machine technique are allocated flexibly and reasonably according to specific screening indexes of work to recover iron carbonate and hematite in raw ore, environmental pollution is light, the technological process is simple, and qualified iron ore concentrate which has the iron grade of more than 65% after sintering and is capable of meeting smelting requirements can be obtained.

A welding stainless steel electrode with improved slag detachability and welding quality is composed of a core and a coated flux layer prepared proportionally from rutile, feldspar, marble, fluorite, wollastonite, megnesite, titaniunm oxide powder, hematite, aluminum fluoride, mice, barium carbonate, Cr, Ni, sodium carbonate, electrolytic manganese and ferrotitanium.