141results about How to "Reduce grinding amount" patented technology

The cooled agglomerated carbon-contained pellet prepared with vanadium titano magnetite concentrate and opposite direct reduction with former pellet comprises: mixing the concentrate, reducer and bonding agent, drying, grinding, and pelletizing to obtain the cooled agglomerated carbon-contained pellet drying and sieving into the reduction furnace with reducer for reduction atmosphere; loading the reduced pellet into electric furnace to melt and separate the iron liquid, V, Ti and Cr. This invention is fit to the pellet on wide application temperature and low energy consumption, has well efficiency and low running cost, and can also extract V, Ti Fe and Cr from electric furnace with high yield and obvious environmental protection.

The invention relates to a gravity-flotation joint separation technology for coking middlings and belongs to the technical field of mineral processing. The technology comprises the steps of crushing the coking middlings, water medium whirlcone gravity concentration, and ore grinding-floatation of gravity concentration middle products. The technology is characterized in that the water medium whirlcone is adopted for gravity concentration, so that equipment is few in link and simple in technology; no heavy media need consuming, so that operation cost is low; head pulling or tail throwing is adopted for gravity concentration, so that subsequent ore grinding materials are made to be reduced in number, and energy consumption is saved.

The invention discloses a low-cost high-recovery environment-friendly mineral separation method of low-grade vanadium titano-magnetite. Medium-intensity magnetic primary iron separation, large-particle strong-magnetic tail throwing, subsequent ore grinding magnetic separation iron separation, strong-magnetic flotation titanium separation are conducted after three segments of crushing including rough crushing, medium crushing and high-pressure roller grinding are conducted, the iron and titanium ore concentrate quality and yield are higher, energy consumption per unit is lower, tailings discharge pressure is smaller, and the production capacity is greatly improved. According to the method, qualified tailings are thrown out in advance through the method that medium-intensity magnetic primary iron separation and strong-magnetic tail throwing are conducted after fine crushing is conducted, so that the subsequent ore grinding amount is reduced, the grade of iron and titanium generated in the subsequent grinding and separation processes is increased, and thus the product cost is reduced. The method is simple in technological process, easy to operate, low in cost and high in ore separation efficiency, the produced product is stable in performance, the production environment is more environmentally friendly, chemical matter generated in the flotation titanium separation production process is greatly reduced, and the pollution is low. The method is not limited by the production scale, the iron and titanium ore concentrate quality and yield are increased while large-particle qualified tailings can serve as by products to increase benefits, so that the enterprise profits can be maximized, and the method has wide application prospects on the aspect of vanadium titano-magnetite separation.

The invention relates to a mineral benefication method for specularite, comprising recycling the iron ore concentrate in the specularite by first-stage coarse grinding, spiral chute sorting, low-intensity magnetic separating, high-intensity magnetic separating, second-stage ore-grinding, spiral chute sorting, high-intensity magnetic separating and reverse flotation separating process, or first-stage coarse grinding, low-intensity magnetic separating, spiral chute sorting, high-intensity magnetic separating, second-stage ore-grinding, spiral chute sorting, high-intensity magnetic separating and reverse flotation separating process. The method has the characteristics of simple process and structure, low investment cost, low production cost, economy and environment protection, and strong flexibility; when the mineral property changes, the iron minerals are sorted and recycled by properly regulating the method.

The invention provides a magnetic ore dressing method. The magnetic ore dressing method comprises the steps of raw core coarse crushing, fine crushing, ZCLA presorting, ore grinding, ZCLA sorting, and strong magnetic flow and weak magnetic flow implementing of ore concentrate subjected to ZCLA sorting. Compared with the general magnetic core dressing process, the magnetic ore dressing method has the advantages that by a section of sorting operation, valuable ores with different magnetic differences and wider particle size range in the magnetic ores can be gathered and sorted, and before the low-magnetic ores are sorted by a strong magnetic separator, the iron does not need to be removed in advance, the sorted particle range is wide, the whole sorting process is simple and the sorting effect is good.

The invention relates to a tooth arrangement method for manufacturing complete dentures, and belongs to the technical field of manufacturing of dental prostheses. The tooth arrangement method for manufacturing the complete dentures comprises the steps that 1, a three-dimensional database of tooth characteristics of standard teeth is established; 2, oral cavity characteristic information of a patient is extracted; 3, tooth arrangement is conducted. According to the tooth arrangement method for manufacturing the complete dentures, a mutual constraint relationship between the oral cavity and artificial teeth is established, and therefore automatic tooth arrangement is achieved; dentitions according with the oral cavity characteristics of different patients are obtained, and the arranged dentitions can be appropriately adjusted according to patient needs so as to accord with the sex, age and the like of the patient; meanwhile, the diagnosis and treatment situations of the patient can be tracked and recorded, taking for use and updating can be achieved at any time, and the clinical needs of the complete dentures can be effectively met.

The invention discloses a low-grade magnetite pre-selection and waste abandoning mineral separation process. The process comprises the following steps: carrying out coarse crushing, carrying out medium crushing, carrying out first-section sieving, carrying out first-section pre-selection and waste abandoning, carrying out fine crushing, carrying out ultrafine crushing, carrying out second-section sieving, and carrying out second-section pre-selection and waste abandoning. After raw ores are subjected to the coarse crushing and the medium crushing, three products are sieved by the first-section sieving; oversize products obtained after the first-section sieving is finely crushed through ore concentrate which is obtained by the first-section pre-selection and waste abandoning to form a fine crushing closed cycle; sized products obtained after the first-section sieving and the oversize products obtained after the second-section sieving are finely crushed and then are returned back to the second-section sieving to form an ultrafine crushing closed cycle; undersize products obtained after the first-section sieving and undersize products obtained after the second-section sieving are subjected to the second-section pre-selection and waste abandoning, and tailings in the first-section pre-selection and tailings in the second-section pre-selection are final tailings; and ore concentrate in the second-section pre-selection is a final product. According to the low-grade magnetite pre-selection and waste abandoning mineral separation process, a plurality of waste stones can be abandoned and the amount of ore entering a mill is reduced; the mill-entering grade of iron ores is improved, and the energy consumption and the consumption of steel balls can be reduced; and the development and the utilization of low-grade magnetite ores are facilitated, and the utilization rate of resources is expanded.

The invention provides a wear resistant cast iron roll collar used for aligning a steel rail and a preparation method, which belong to the technical field of steel rail processing. The prior wear resistant cast iron roll collar used for aligning the steel rail has the defects of easy occurrence of cracks, complicated manufacture process and the like in quenching process. The method is to compound a wear resistant outer layer with a magnesium iron inner layer into an integral roll collar by centrifuge casting, wherein the wear resistant outer layer comprises the following ingredients in weight percentage: 3.0 to 3.4 percent of C, 1.5 to 2.0 percent of Si, 1.2 to 1.6 percent of Mn, 0.2 to 0.4 percent of Nb, 0.03 to 0.06 percent of RE, 0.03 to 0.06 percent of Mg, 2.5 to 3.0 percent of Ni, 0.4 to 0.6 percent of Mo, 0.8 to 1.2 percent of Cu, 1.5 to 1.8 percent of Cr, 1.0 to 1.4 percent of V, 0.03 to 0.08 percent of B, 0.002 to 0.005 percent of Te, 0.01 to 0.03 percent of Ba, less than or equal to 0.06 percent of P, less than 0.03 percent of S, and the balancing being Fe. The invention has the advantages of high hardness of the roll collar, good wear resistance, simple production process and low production cost.

The invention relates to the technical field of ore beneficiation, and in particular relates to an extremely lean magnetite beneficiating process. The process is characterized by comprising the following steps of: 1) carrying out wet pre-beneficiation on raw ores with grain sizes being 0-5mm and concentration being 35-45%; 2) processing the concentrates obtained through wet pre-beneficiation with a primary closed-circuit milling system formed by primary ball milling and primary classifying and discarding the tailings obtained through wet pre-beneficiation; 3) carrying out first-stage magnetic separation on overflow obtained through primary classifying; 4) processing the concentrates obtained through first-stage magnetic separation with a secondary closed-circuit milling system formed by secondary ball milling and secondary classifying; 5) carrying out second-stage magnetic separation on overflow obtained through secondary classifying; 6) carrying out third-stage magnetic separation on concentrates obtained through second-stage magnetic separation; 7) taking the concentrates obtained through third-stage magnetic separation as the final concentrates with grades being 63-64%; and 8) discarding the final tailings formed by the tailings obtained through first-stage magnetic separation, second-stage magnetic separation and third-stage magnetic separation. The process has the following characteristics that: 30% of tailings are discarded by adopting the pre-beneficiation method, thus improving the beneficiation feed grade of the ores to 16-18%, reducing the quantity of the ores entering the ball mill by 30% and obviously lowering the ore beneficiation cost; and the energy is saved and the economic benefits are obvious.

The invention provides a beneficiation method for a high-carbon molybdenum nickel ore, which adopts floatation decarbonization so as to eliminate the influence of high-content carbon substances on subsequent nickel floatation. Furthermore, the beneficiation process adopts sieve classification with jigging and tail throwing so as to enhance the floatation and selected grade, then rough concentrates are selected again and treated by floatation after being ground, and the ore concentrates are selected again with tail throwing to enhance the floatation and selected grade without ore grinding. The invention can greatly reduce the floatation quantity, has good beneficiation index and provides a new way for developing a low-grade high-carbon molybdenum nickel ore.

The invention provides a separation method for treating low-grade refractory zinc lead oxide ores, which adopts a full heavy separation process. The method is implemented in a way that: all raw ores are crushed into particles of which the maximum particle size upper limit is 20-5mm; the crushed ores are screened into two size grades +0.5mm and -0.5mm; and the two size grades of crushed ores are respectively subjected to heavy-media separation and rocker re-separation to obtain lead-zinc mixed concentrate products which can be used as raw materials for the next technical step of oxygen pressure acid leaching. The technical process is simple and easy to operate; and the invention has the advantages of lower ore grinding amount, low separation cost, no need of any reagent, small environmental pollution, favorable technical indexes and the like, can recycle the backwater, greatly enhances the recovery rate of metals lead and zinc, and achieves the goals of energy saving, emission reduction, consumption reduction and comprehensive utilization of resources on the whole.

The invention relates to a new three-stage, one-closed-circuit, two-stage pre-selection crushing process. The steps are as follows: Send the raw ore to a coarse crusher for crushing, and its discharge enters a section of vibrating screen for classification, and the products on the screen enter a section of magnetic pulley, and a section of magnetic pulley for separation The output concentrate enters the intermediate crusher for crushing, and the sorted waste rock enters the waste rock bin. The product of the intermediate crusher enters the second-stage vibrating screen together with the under-screen product of the first-stage vibrating screen, and the over-screen product of the second-stage vibrating screen enters the second-stage vibrating screen. The second-stage magnetic pulley, the waste rock separated by the second-stage magnetic pulley enters the waste rock bin, the concentrate separated by the second-stage magnetic pulley enters the fine crusher for crushing, and the crushed product of the fine crusher and the product of the intermediate crusher are combined into the The second-stage vibrating screen is classified, and the under-screen product of the second-stage vibrating screen enters the dry magnetic separator, and the concentrate of the dry magnetic separator is sent to the final product for grinding, and the separated waste rock enters the waste rock bin. By adopting the new process of the present invention, waste rocks can be removed to the greatest extent before grinding, the amount of ore input can be reduced, and the purpose of saving energy and reducing consumption can be achieved.

The invention discloses an enrichment method for chambersite. The method comprises the steps that products of three size fractions of +0.5 mm, -0.5-+0.15 mm and -0.15 mm are crushed and screened; the products of the size fraction of +0.5 mm are scrubbed, ground and subjected to desliming to obtain first concentrate; the products of the size fraction of -0.15 mm are subjected to flotation to obtain second concentrate; and the first concentrate and the second concentrate are mixed to obtain mixed concentrate. The enrichment method for chambersite has the beneficial effects that only the products of the coarse size fraction are scrubbed and ground, so that the amount of grinding is greatly reduced, energy consumption is reduced, and grinding media are not used during the scrubbing and grinding links; the grade of the chambersite is improved to above 90% by screening and primary rough flotation of chambersite concentrate with the chambersite content of about 50%, and the recovery rate is more than 75%; concentration and scavenging are not needed during the flotation link, so that the time is shortened greatly, and the cost is reduced; the method is easy and convenient to operate and popularize.

The invention relates to a magnetite high-pressure roller mill-wet type preconcentration-stage grinding-tower mill magnetic separation technology. The magnetite high-pressure roller mill-wet type preconcentration-stage grinding-tower mill magnetic separation technology comprises rough breaking operation and intermediate breaking operation and is characterized in that products obtained by the intermediate breaking operation are subjected to the following operations in sequence: closed-loop high-pressure roller mill-sieving operation formed by a high-pressure roller mill and sieving equipment, wet type preconcentration magnetic separation operation, one-stage closed-loop ore grinding operation, second-stage closed-loop ore grinding operation formed by secondary cyclone grading and a second-stage tower mill and continuous three-stage magnetic separation operation, so that final concentrate with the grade being 67%-67.8% and the yield being 38%-41% and integrated tailings with the grade being 8.5%-9.5% and the yield being 62%-59% are obtained. The magnetite high-pressure roller mill-wet type preconcentration-stage grinding-tower mill magnetic separation technology has the advantages that a high-pressure roller mill is used for preconcentration, so that the size of particles fed into the mill is reduced, and the grade of crude ore and the fineness of grinding are improved; the second-stage closed-loop ore grinding operation formed by the cyclone and the tower mill is adopted; the fine screening-regrinding operation is omitted; the fifth-stage magnetic operation is reduced; the technology process is simplified; and the beneficiation cost is reduced.

The invention discloses an external-circulation cement finish grinding system for a vertical mill. The external-circulation cement finish grinding system comprises a belt conveyor, a bucket elevator, a steady current bin, a vertical mill, a dust collector, a fan and a chute, wherein the belt conveyor is used for conveying materials inside, and the chute is used for conveying fine powder finished products outside. The external-circulation cement finish grinding system is characterized in that the bucket elevator, a coarse powder concentrator, the steady current bin and the vertical mill are sequentially connected to form a circulating system; the bucket elevator, the coarse powder concentrator, a refined powder concentrator, the steady current bin and the vertical mill are sequentially connected to form a circulating system; the bucket elevator, the coarse powder concentrator, the refined powder concentrator, the dust collector and the fan are sequentially connected; a powder concentration device is positioned outside the vertical mill and is formed by serially connecting the coarse powder concentrator and the refined powder concentrator; the coarse powder concentrator comprises three paths of air inlet pipelines which are connected in parallel, one path is connected with a heat source, one path is connected with cold air, and one path is connected with a dust collecting air inlet of the vertical mill.

The invention belongs to the technical field of spray drying, and discloses a spray drying tower for preparing powder. The spray drying tower comprises a tower body, wherein the tower body is provided with a hot air supply device, an exhaust device and a slurry-feeding atomization device; the bottom of the tower body is provided with a powder outlet; a plurality of tower air inlets of the hot airsupply device are formed on the inside walls of the middle part and the lower part of the tower body, and the temperature of the tower inlet hot air is gradually reduced from bottom to top; and the exhaust port of the exhaust device is formed on the upper part of the tower body. Through counter flow type structural design, the slurry is first contacted with the low-temperature hot air in the tower and then contacted with medium-temperature and high-temperature hot air in turn to generate solid spherical powder so as to effectively solve and improve the technical problems of the prior art. Thespray drying tower can make full use of waste heat, reduce energy consumption and reduce emission; and the ceramic powder treated by the tower can achieve the technical effects of improving the pressing forming efficiency, increasing the strength of the blank, reducing sintering shrinkage, reducing planed edge polishing quantity and the like. The spray drying tower is also suitable for other spray drying powder preparation processes.

The invention relates to a size-fractionated pre-selection tailing discarding process of extremely-poor hematite. The process comprises a step of carrying out semi-autogenous grinding to obtain semi-autogenous grinding discharge ore with a particle size of 14-0mm. The process is characterized by screening; carrying out coarse grain pre-selection I; carrying out coarse grain pre-selection II; carrying out first-section closed-circuit grinding; carrying out coarse grain pre-selection operation III; and carrying out second-section closed-circuit grinding. A three-layer linear vibrating screen isadopted for screening. In four products, the product with a size fraction of-14 mm to 10 mm is returned to semi-autogenous grinding. The coarse grain pre-selection I and the coarse grain pre-selectionII are used for pre-selecting a -10mm-6mm size fraction and a -6mm-2mm size fraction. Coarse-grain tailings are thrown out, coarse-grain concentrates are combined and fed into first-section closed-circuit ore grinding, a first-section closed-circuit ore grinding product and the screened -2 mm size fraction are fed into coarse-grain pre-selection operation III for pre-selection tailing discarding,coarse-grain pre-selection operation III concentrates are fed into second-section closed-circuit ore grinding, and second-section closed-circuit ore grinding overflow is fed into subsequent sorting operation. The process has advantages that discharge ore is divided into narrow grades for respective pre-selection; qualified coarse grain tailings are thrown out; and a problem of stubborn stone accumulation is solved, and a processing capacity of a semi-autogenous mill is improved.

The invention discloses a mineral processing method for efficiently recovering fine-grained low-grade magnetite. Iron concentrate I and tailings I can be obtained by weak magnetic separation with a magnetic induction intensity of 1100-1300Oe; iron concentrate II and tailings II can be obtained from tailings I by strong magnetic separation with a magnetic induction intensity of 0.9-1T; iron concentrate I and iron Concentrate II is combined and ground to -0.045mm, accounting for 75-85% to obtain fine-grained ore II; fine-grained ore II is subjected to weak magnetic separation with a magnetic induction intensity of 1000-1200Oe to obtain iron concentrate III and tailings III; Iron concentrate IV and tailings IV are obtained by strong magnetic separation with a magnetic induction intensity of 0.560-0.783T, and iron concentrate III and iron concentrate IV are combined to obtain a total concentrate, and tailings II and tailings IV are combined to throw tailings. The invention has the characteristics of short process flow, less grinding amount, high beneficiation efficiency, iron recovery rate and high concentrate grade.

The invention relates to a vanadium titano-magnetite screening method and belongs to the field of ore screening. The technical problem to be solved in the invention is to provide a vanadium titano-magnetite screening method. The vanadium titano-magnetite screening method comprises the following steps: a, tail-escaping, namely performing tail-escaping on vanadium titano-magnetite with the granularity of less than or equal to 12mm so as to obtain tail-escaping concentrate; b, performing primary grinding and magnetic separation, namely grading the tail-escaping concentrate to prepare 40-45 percent ore pulp of which the granularity is -200 meshes, and performing magnetic separation to obtain primary concentrate; c, performing secondary grinding and magnetic separation, namely demagnetizing the primary concentrate obtained in the step b and performing secondary grinding, grading to prepare 75-80 percent ore pulp with the granularity of -200 meshes, and performing magnetic separation to obtain secondary concentrate; and d, performing third-stage magnetic separation, namely performing magnetic separation on the secondary concentrate obtained in the step c so as to obtain iron ore concentrate. According to the vanadium titano-magnetite screening method, the TFe content of iron ore concentrate obtained by utilizing low-grade vanadium titano-magnetite is 55-57 percent, the quality is stable, and the method has the advantages of low cost, environment friendliness and energy conservation.

The invention discloses a kind of modified oil-well cement, a preparing method thereof and a production line thereof. The modified oil-well cement comprises components of cement clinker, gypsum and at least two mineral additives, and by mass ratio, the cement clinker occupies 20%-80%, the gypsum occupies 2%-10%, and all the mineral additives respectively occupy 0.1%-40%. The preparing method includes metering, dosing and grinding all components to form cement in a preset granular level, or independently grinding all components or metering and dosing all components in proportion and grinding all components in groups, and then metering and dosing all components in proportion and mixing all components evenly to obtain the cement. The production line comprises a metering and dosing system and a cement grinder, wherein the metering and dosing system meters, doses and mixes all components in proportion, and the cement grinder grinds mixed materials to cement in the preset granular level. Or the production line comprises a grinding system and a mixing stirrer, wherein the grinding system grinds all components independently or meters and doses all components in proportion and grinds all components in groups to be in the preset granular level, and the mixing stirrer evenly mixes powder materials of all components to be cement. The modified oil-well cement obtained through the preparing method and the production line properly reduces production cost on the basis of meeting the product performance index.

The invention relates to a magnetite high compression rolling wet pre-concentration-stage grinding-fine screen tower rolling magnetic separation process. The process comprises coarse breaking and mildbreaking, and is characterized by further comprising the following steps that ores with the grade being 30%-32% and the granularity being -25mm are subjected to closed circuit high compression rolling; rolling products are subjected to beforehand magnetic separation; premagnetization concentrates are subjected to first-stage closed-circuit grinding; primary overflow is subjected to first-stage magnetic separation; first-stage magnetic separation concentrates are subjected to second-stage closed-circuit grinding; secondary overflow is subjected to second-stage magnetic separation and fine screening; screen residues are subjected to third-stage closed-circuit tower milling and grinding; third-time graded overflow products are graded by a third-stage magnetic separator; concentrates of the third-stage magnetic separator and screen underflow products are subjected to fine magnetic separation to obtain 67%-67.5% final concentrates; and tailings of all stages of magnetic separation work arecombined to be combined tailings. The magnetite high compression rolling wet pre-concentration-stage grinding-fine screen tower rolling magnetic separation process has the advantages that (1) high compression rolling pre-concentration is conducted, so that the particle size of grinding feed is reduced, and the grade of crude ores and grinding fineness are improved; (2) a cyclone and a tower millare combined, so that one stage of fine screening and multiple stages of magnetic separation operation are omitted; (3) the flow is simplified, and the ore mineral separation cost is lowered.

The invention belongs to the technical field of ore dressing in metallurgy and mining industry, in particular relates to a three-stage pre-dressing and crushing process for low-grade magnetite. The process comprises the following steps of: feeding magnetite into a coarse crushing machine, transferring the material discharged from the coarse crushing machine to a first-stage dry-type magnetic pulley by using a rubber belt machine, delivering first-stage ore concentrate products to a middle crushing machine by using the rubber belt machine via a middle crushing machine ore bin, delivering middle crushing machine products to a second-stage magnetic pulley by using the rubber belt machine, screening ore concentrate products by a sieving machine to obtain on-sieve products and under-sieve products, crushing the on-sieve products by a fine crushing machine and mixing the crushed on-sieve products with the products crushed by the middle crushing machine, and then transferring the mixedcrushed products to the sieving machine, delivering the under-sieve products to a third-stage dry-type magnetic separation machine by a belt conveyer, wherein ore concentrates discharged from the from the third-stage dry-type magnetic separation machine are taken as the crushed final products, and waste stone from the magnetic separation machine is stored in a waste stone bin. According to the invention, the dry-type magnetic pulley operation is performed after the coarse crushing operation and the dry-type magnetic separation machine operation is performed after the fine crushing operation, the tailing rejection is performed in advance, therefore the milling grade can be improved and the ore grinding load can be reduced, and further, the purposes of reducing the energy consumption and increasing the economic benefits of ore dressing plants can be achieved.

The invention relates to a depth-induced crushing mineral separation technology of super-lean magnetic iron ore, which is applied to the technical field of mineral separation of super-lean magnetic iron ore. The technology comprises the following steps: after coarsely crushing and intermediately crushing the super-lean magnetic iron ore by adopting a gyratory crusher and a cone crusher respectively, performing one-stage magnetic-pulley dry discarding pre-separation, performing two-stage magnetic-pulley dry discarding on tailings, and finely crushing the fine ore through a hammer crusher; sieving the finely crushed product, returning the fine ore for fine crushing operation, and sieving the tailings to serve as a gravel aggregate product; performing dry separation on ore concentrate, milling ores by adopting a ball mill, and performing once coarse separation, twice fine separation, once concentration and once filtration to obtain dry ore concentrate; performing selective grinding on the tailings, concentrating by a concentrator, filtering through a filter, and performing dry heaping on the filtered tailings and the tailings from the dry separator. According to the super-lean magnetic iron ore which contains about 5% of magnetic iron, the tailings after dry discarding are sieved to serve as the gravel aggregate product for depth-induced crushing, the feeding amount is reduced, the mineral separation cost is reduced, and the economic benefits are obviously improved.

The invention relates to a magnetite crushing, pre-separating and mineral milling process which comprises a crushing and dry separating operation. The magnetite crushing, pre-separating and mineral milling process is characterized by further comprising a closed-loop roller milling operation, a pre-separating operation and a closed-loop tower milling operation; the closed-loop roller milling operation is performed through a high-pressure roller mill and a vibration screening machine; the pre-separating operation is performed through a dry pre-separating magnetic separator; and the closed-loop tower milling operation is performed through a tower mill and a swirler. According to the magnetite crushing, pre-separating and mineral milling process, a crushing and dry separating operation productof which the particle size reaches negative 30 mm is treated through the above three operations in sequence; a process product of which the particle size reaches negative 0.074 mm and the content reaches 85% to 95% is obtained; and the particle size requirements of follow-up selective operations are met. The magnetite crushing, pre-separating and mineral milling process provided by the inventionhas the following advantages: (1) the mill feeding particle size is reduced from negative 12 mm to negative 3 mm, the mill feeding grade is improved by 5% to 10%, and the mill feeding amount is reduced by about 20%; and (2), the fine crushing operation burden is greatly relieved, the existing mineral milling process is simplified, the capital construction investment is greatly reduced, the mineralseparating cost is reduced, the energy is saved, the consumption is lowered, and the significant economic benefits are achieved.

The invention discloses mold powder for continuous casting of low nickel and high manganese stainless steel and a preparation method thereof. The mold powder comprises the following chemical compositions in percentage by weight: 38.0 to 42.0 percent of CaO, 32.8 to 38.0 percent of SiO2, 3.6 to 5.0 percent of MnO, 2.0 to 4.0 percent of MgO, 3.0 to 4.0 percent of Al2O3, 10 to 14 percent of fluxing agent containing NaO, F and Li2O, and 1.5 to 2 percent of Fc, wherein the ratio of the Cao to the SiO2 is 1.0-1.28. The preparation method comprises that: various raw materials are mixed and pelletized; and the pellets are melted in a liner-free furnace with water-cooling wall, subjected to water quenching, drying and crushing, added with a carbon material, namely 1.5 to 2.0 percent of Fc, and then prepared into hollow spherical mold powder in a spray prilling tower. Compared with the prior art, the mold powder has the advantages of eliminating vertical cracks on the surface of a casting blank, preventing cinder inclusion on the surface of the casting blank, avoiding oscillation marks on the casting blank, reducing surface conditioning of the casting blank, and having the surface quality of a slab equal to 304 austenitic stainless steel.

The invention discloses an efficient environment-friendly type beneficiation method for low-grade magnetic mirror iron ores. The efficient environment-friendly type beneficiation method is characterized in that iron ore concentrate which meets smelting requirements is obtained by adopting processes such as raw material three-stage crushing, large particle medium-magnetism and SLon strong-magnetismpre-selection, one-stage ore grinding and grading, one-stage weak magnetic-selecting and one-stage SLon strong magnetic-selecting, pre-grading and two-stage ore grinding and grading, two-stage weak magnetic-selecting and two-stage SLon strong magnetic-selecting and SL centrifugal machine selecting operation for the magnetic mirror iron ores. The efficient environment-friendly type beneficiation method can throw 21% of coarse-particle barren rocks through high-pressure roller-grinding, large-particle medium-magnetism pre-selecting and SLon strong-magnetism pre-selecting, and meets the beneficiation principle of preferably crushing instead of grinding and throwing as early as possible. A selecting process of roughing, cleaning and scavenging of a centrifugal machine is adopted, so that re-selecting operation completely replaces reverse flotation operation, and therefore, the efficient environment-friendly type beneficiation method is a pollution-free beneficiation method, is high in degree of automation, is great in processing amount, is liable to realize field operation and implementation, and greatly reduces manual operation.

The invention discloses a preparation method of a micro order niobium foil. According to the method, three rolling process reversible type rolling is performed on a niobium belt by utilizing a Sendzimir twenty-roller cold rolling machine, the obtained niobium foil is cleaned, and subjected to edge splitting and heat treatment after each rolling process reversible type rolling, and finally, the micro order niobium foil is obtained. According to the method, three rolling process rolling is performed on the niobium belt with the width being 100 mm to 120 mm and the thickness being 0.15 mm to 0.2mm by adopting the Sendzimir twenty-roller cold rolling machine. Due to the beneficial effects that the Sendzimir twenty-roller cold rolling machine is large in rolling force and high in rolling precision, by designing a reasonable rolling process, the thickness precision of the micro order niobium foil is greatly guaranteed; meanwhile, through a reasonable annealing process, the structure internal stress of the niobium foil is eliminated in time, influences on the niobium foil in the rolling process are reduced, and finally, the micro order niobium foil with the thickness being 0.007 mm to 0.009 mm is obtained.

The invention discloses a method for titanium and iron separation and upgrading of titanium rough concentrate of beach placer. The method comprises the following steps of adding a solid reducing agentinto the titanium rough concentrate, and carrying out reduction roasting by using a rotary kiln to obtain calcine; carrying out water quenching on the calcine, then carrying out gravity separation onthe calcine through a shaking table to recover excessive solid reducing agent to obtain a reducing agent and heavy concentrate; performing two-stage low-intensity magnetic separation on the heavy concentrate to obtain iron rough concentrate and titanium concentrate; and carrying out fine grinding on the iron rough concentrate, and carrying out separation by adopting low-intensity magnetic separation to obtain magnetite concentrate and secondary titanium concentrate. According to the method for titanium and iron separation and upgrading of the titanium rough concentrate containing hematite alteration, titanium and iron are efficiently separated, the quality of the titanium concentrate is improved, meanwhile, the iron concentrate is recovered, the process is simple, no medicament pollutionexists, the process is easy to operate, and the method is convenient to popularize.

The invention belongs to the field of beneficiation of black metal ore, and particularly relates to a beneficiation method for magnetic mixed ore. The beneficiation method for the magnetic mixed ore comprises the steps of pulverization of raw materials, pre-beneficiation of the pulverized raw materials, treatment of screened rough concentrate, and treatment of screened tailings. A rough concentrate primary-grading procedure used for screening the rough concentrate is additionally conducted after pre-screening of the raw materials and before treatment of the rough concentrate. Compared with a conventional magnetic ore beneficiation technique, a ZCLA preseparator is used for wet screening of products which are fine pulverized through a closed circuit and ultrafine pulverized through an open circuit, 20% of barren rocks in magnetic iron ore can be effectively removed, and grading can be achieved in advance through pre-screening of the concentrate, and thus part of products with qualified granularities directly enter the next production procedure; and the grinding quantity can be effectively reduced, the probability of excessive grinding is lowered, the grinding grade and the ore grinding efficiency are improved, and energy consumption for ore grinding is reduced.