114 results about "Chrome ferroalloy" patented technology

The invention relates to a process and a device for smelting chromium irons and chromium-containing molten iron by using chromium ore powder, which belongs to metallurgical industry steel-making raw material. The process comprises the following steps: mixing chromium iron containing raw materials with reducing agent, solvent and catalyst to prepare ultra fine powder, mixing to make pelletizing materials, sending the pelletizing materials into a reducing furnace, obtaining chromium irons pellets after the reduction reaction, and directly adding reduced pellets into a lining electroslag furnace for being smelted into the chromium-iron alloy or the chromium-containing molten iron. The device comprises an internal-external heating vertical reducing furnace, a lining electroslag furnace and a residual heat recovery system. The invention has the advantages that: firstly, the reduction temperature is low, the speed is high, the energy consumption is reduced, the production cost is lowered, the production efficiency is high, and the uniformity of the quality is good; secondly, the degree of mechanization is high, the procedure is simple, the yield is large, the mass production can be performed; thirdly, the waste of raw materials is reduced, the environment pollution is lowered; fourthly, the source of raw materials adopting the chromium ore powder and chromium-containing waste, the cost is low; fifthly, the waste resource can be recycled so as to save the resource consumption; and sixthly, the high-temperature pellets are directly smelted by adopting the lining electroslag furnace, the heat efficiency is high, the energy consumption is low, the material purity is high and the quality is good, and the device is simple with less investment.

The present invention relates to a method for directly producing ferro chromium with chrome powder and coal. The chrome powder and the coal powder, etc are produced into carbon-bearing pellets, and the reaction temperature is controlled below the pellet soft melting temperature. The slag phase alkalinity is enhanced, to increase the reaction temperature as far as possible, thereby speeding up the reaction speed and improving the metal percent reduction. During the cooling process, the high alkalinity metallised pellet is naturally pulverized because of the existence of thermal stress and excessive carbon powder, and the ferro chromium can be obtained by sieving. Harmful elements of P, S, etc in the raw material are mainly reserved in the slag phase, and thereby the ferro chromium with low P and S content can be obtained. The method of the present invention replaces the traditional electric arc furnace smelting method, provides the ferro chromium with low cost for the smelting and the production of stainless steel, and reduces the dependence of the production of the ferro chromium on a large amount of electric power and lump ore. The ferro chromium is ferro chromium with low P and S content.

The method of producing Ni-Cr agglomerate for smelting Ni-Cr-Fe alloy in blast furnace with Ni-Cr ore and industrial Ni-Cr waste includes mixing industrial Ni-Cr waste, Ni-Cr ore of granularity smaller than 10 mm, flux, coke powder and water in the first mixer; pelletizing the mixture in the second mixer; sintering the pellet in a sintering bogie, and sieving to obtain Ni-Cr agglomerate and returned material. The produced Ni-Cr agglomerate is used for smelting Ni-Cr-Fe alloy in blast furnace together with other material.

The invention discloses a manufacturing method of stainless steel mother liquor foam slag through electric furnace dephosphorized molten iron, which comprises the following steps: 1)adding solid material with waste stainless steel, ferrochromium and silicon into electric furnace through material basket; energising to smelt; setting the quantity of siliconat at 8.5-12kg/t; 2)adding dephosphorized molten iron when the power consumption is 15-22 Mwh; controlling C content of mother liquor at 1.50-4.00%; 3)forming basic smelting pond in the furnace when the power consumption is 160-200Kwh/t; starting to blow carbon powder with content at 2-4kg/t; jetting oxygen with quantity at 2500Nm3/h-3500Nm3/h.

The invention provides a method for smelting stainless steel by a top-bottom blowing converter, which comprises the following procedures: I. adding ion melt into the top-bottom blowing converter, adding coke, blowing oxygen and argon to smelt; II. when the molten steel temperature is more than 1600 DEG C, adding ferromanganese iron, chromium iron alloy, blowing oxygen and argon to smelt, adding slag to adjust the slag; III. when the molten steel temperature is more than 1630 DEG C, adding again ferromanganese iron, chromium iron alloy, blowing oxygen and argon to smelt, adding slag to adjust the slag; IV. when the actually measured temperature of the molten steel is more than the calculated temperature, adding the remainder alloy ferromanganese iron, chromium iron and nickel, blowing oxygen and argon to smelt, adding lime and small amount of fluorspar to adjust the slag; V. reducing gradually the blown oxygen and increasing the blown argon; VI. stopping blowing oxygen from bottom but only blowing argon, agitating 1.5-2.5 min.; VII. adding silicon iron and adding slag; VIII. blowing argon from bottom for reducing and agitating for >=5 min.; IX. sampling and analyzing components, and tapping steel. The present method for smelting stainless steel by a top-bottom blowing converter is of low cost.

The ferritic stainless steel mother liquid smelting process in the charge mixture mode of dephosphorized molten iron+waste carbon steel+ferrochromium includes the following steps: feeding dephosphorized molten iron, waste carbon steel and ferrochromium and powering on; adding ferrosilicon after powering for 2.0-4.0 Mwh; beginning oxygen blast after powering for 5.0-7.0 Mwh; regulating the oxygen flow rat to 2500 Nm3/h and total oxygen amount to 9-10 Nm3/t after power consumption reaches 8.0-12.0 Mwh; adding lime after power consumption reaches 7.0-10.0 Mwh; spraying carbon powder after power consumption reaches 16.0-20.0 Mwh; adding dolomite after power consumption reaches 15.0-18.0 Mwh; reducing after power consumption reaches 220-240 Kwh/t and the measured temperature reaches 1610 deg.c; and tapping after power consumption reaches 250-320 Kwh/t and the measured temperature reaches 1630-1660 deg.c. The present invention has low power consumption and other advantages.

A ferrochrome alloy is produced from an ore or concentrate by smelting the ore or concentrate in the presence of a reductant which is a carbide alone or a carbide in combination with another reductant. The carbide is preferably silicon carbide.

The invention discloses a method for jointly producing chromium salt and ferrochromium alloy by sintering with the wet-fire methods, comprising the following steps: grinding coarse ferrochromium ore into fine ferrochromium ore powder; mixing the fine ferrochromium ore powder and sodium carbonate into mixture, and sintering the mixture into primary sintered clinker; extracting primary sodium chromate solution from the primary sintered clinker and obtaining the left primary chromium slag; separating, sintering and crushing the primary chromium slag into primary chromium slag powder, and mixing the primary chromium slag powder and sodium carbonate into mixture, and sintering the mixture into secondary sintered clinker; extracting secondary alkaline sodium chromate solution from the secondary sintered clinker and obtaining the left secondary chromium slag; adding acidic solution to neutralize the alkaline sodium chromate solution; adding sodium dichromate to the sodium chromate solution, adjusting the acidifying with sulfuric acid to form sodium dichromate solution, and separating sodium dichromate crystals from the sodium dichromate solution; mixing the secondary chromium slag and iron ore with coke powder and auxiliary materials and sintering the mixture into sintered ore; and mixing the sintered ore and coke in a blast furnace to smelt the ferrochromium alloy.

The invention relates to a method for smelting magnesium and co-producing ferrochrome-containing liquid with a ferrosilicon bath stair reduction silicothermic method, belongs to the technical field of nonferrous magnesium metal extraction and also belongs to technical field of chromium-containing stainless steel and ferrochrome smelting of ferrous metallurgy. Ferrosilicon bath much higher in theoretical chemical demand quantity is used as a silicothermic reducing agent and carrier of chemical reaction, reaction interfacial area is increased and convective heat transfer and mass transfer abilities are strengthened to realize reinforcement of reduction process through intense stirring. After reduction is completed, magnesium smelting reduction slag is eliminated, excessive ferrosilicon is mixed with a new batch of magnesium ore to smelt magnesium until the concentration of ferrosilicon liquid is lower than that of lower silicon, and lower ferrosilicon liquid is mixed with chrome ore to carry out chromium reduction to obtain chromium-containing stainless steel mother liquid. The excessive ferrosilicon bath is respectively used for smelting magnesium and ferrochrome at high concentration and low concentration, ferrochrome raw material is completely utilized, the reaction efficiency is high, energy is saved, carbon, phosphorus and sulphur in the ferrochrome liquid are little, and the co-production cost of magnesium and stainless steel liquid is obviously reduced in comparison with sum of the production cost of magnesium and the production cost of stainless steel liquid.

The invention relates to a preparation method for mother liquid of nickel chrome stainless steel. The preparation method comprises the steps that laterite-nickel ore, chromite fine ore, a carbonous reducing agent and an annexing agent are evenly mixed according to the mass ratio of 40%-60% : 20%-40% : 8%-15% : 1%-6%, a mixed material is obtained, wherein the water content of the laterite-nickel ore is 5%-20%; the mixed material is pressed into balls and dried, and pellets are obtained; and the pellets are roasted under a reducing atmosphere at 1250-1400 DEG C, and pre-reduced pellets are obtained; and the pre-reduced pellets are transported to a smelting furnace in a hot transportation mode to be smelted, and then the mother liquid of the nickel chrome stainless steel is obtained after slag-iron separation. According to the preparation method for the mother liquid of the nickel chrome stainless steel, the smelting cycle is shortened, the materials are extensive in source and low in price, and the smelting cost of stainless steel is reduced greatly; and compared with the prior art in which the treatments on ferro-nickel and ferrochrome are two independent technologies correspondingly, the preparation method for the mother liquid of the nickel chrome stainless steel overcomes the defects that existing technologies are complex, the technological process is long, the energy consumption is high, pollution is severe, and the operation cost is high, and the energy consumption of smelting of an electric furnace is effectively reduced.

The invention discloses a manufacture technology for an anti-corrosion, low-cost, refined and environment-friendly stainless steel wire. The manufacture technology comprises the technological steps that ingredients including ferrochrome and ferronickel are used; the ingredients are successively put into an electric arc furnace for heating and melting; contents of each of the elements are detected,and temperature preservation is conducted during detection; each of the chemical ingredients is adjusted again according to detection results; then, slagging is conducted; and slagging-off and steeltapping are carried out when a furnace temperature reaches 1650 DEG C; a spiral flow duct of which the height is lower than the bottom wall of a furnace cavity is disposed at an outlet of the electricarc furnace; the detected elements include C, Si, Mn, Cr, Ni, P and S; after entry of molten steel in a primary forging furnace, a mixed gas of Ar (N2) + O2 is blown into the furnace, the content ofN is detected, and a blowing process is divided into an oxidation stage, a reduction stage and a refinement stage; continuous casting is carried out; and the wire is manufactured after continuous rolling. The manufacture technology disclosed by the invention has the beneficial effects that the molten steel with the uniform ingredients can be obtained through opening or closing of a molten steel valve during molten steel taking, so accuracy of the detection results is increased, cost is reduced and production efficiency is increased; and on the premise that stainlessness is not reduced, the content of Ni is reduced, but a corrosion resisting rate is increased.

A process for producing chromium iron alloys suitable for steel making directly from chromite ore wherein fines of chromite ore with additions of carbon fines, and accelerant and a binder are agglomerated and the dry agglomerates are fed into a reaction vessel with natural gas as a reducing agent at elevated temperatures adequate for reduction for thereby producing a chromium iron alloy suitable for steel making. The preferred accelerant is an alkali in the form of an oxide, hydroxide or carbonate, sodium hydroxide being preferred.

The invention discloses a low-cost high-corrosion-resistance steel bar and a production method thereof. The steel bar comprises the following chemical components: less than or equal to 0.05% of C, 0.005-0.05% of N, less than or equal to 1% of Si, less than or equal to 1% of Mn, 7.5-10% of Cr, more than 0 and less than or equal to 1% of Mo, 0.01-0.2% of V, 0.02-0.1% of C + N, 1-2% of Si + Mn, 8.5-11% of Cr + Mo + V and the balance of Fe; and the equivalence ratio of chromium to nickel is 7-9. In the production method, ferrochrome is added in two batches during steelmaking; the first batch of ferrochrome is added in converter smelting; the second batch of ferrochrome is added in LF furnace refining, and the ferrochrome accounts for 1/2-2/3 of the total amount; and the temperature of a cooling bed on the steel bar is greater than or equal to 840 DEG C, and the cooling speed is controlled to be less than or equal to 1.5 DEG C/s. The steel bar is excellent in corrosion resistance and mechanical property, low in cost and suitable for use requirements of ocean engineering.

The invention discloses a converter chromium-preparation method for low-carbon Cr-containing alloy steel, belonging to the converter steelmaking field. According to the converter chromium-preparation method, oxygen blowing is stopped after decarbonization and heating in a later smelting period of a converter, ferrochromium alloy is added, the steel is discharged after the terminal temperature and the carbon content reach the standards, aluminum is added into a steel ladle in a steel discharging process so as to carry out deoxygenation, and the Cr content of molten steel reaches 5.0%-5.3%. The converter chromium-preparation method for low-carbon Cr-containing alloy steel has the beneficial effects that the alloy is mainly high-carbon ferrochrome and is reasonably matched with micro-carbon ferrochrome, the alloy cost is low, the yield of the Cr element is high, a terminal molten steel carbon content meets the processing capacity of subsequent vacuum refining, meanwhile, the step of adding silicon iron or aluminum powder to reduce the Cr element in the residue is omitted, the production cost is low, and the economic benefit is good.