Iron series of tungsten alloys, is composed of iron and tungsten alloy, used as a steel alloy additive. Commonly used tungsten iron with tungsten 70% and 80% two kinds. Tungsten ***elting iron use the electric stove, due to high melting point, can"t liquid out, so the agglomerate method or take tiefa production. Before the 1930 s general use ***all (100 ~ 500 kva) single-phase electric arc furnace lump method for ***elting, then switch to three-phase electric furnace, a legacy take tiefa.

China"s jiangxi, hunan, ***gdong a tungsten mine with a lot, reserves of the world 60 to 70%. 1936 ~ 1938 in jiangxi jian preparation tungsten iron works, is equipped with the 2000 kva three-phase agglomerate method of electric furnace two, has built in, because of the war of resistance against Japan after the influence and halt. Since 1955, jilin ferroalloy plant began to take with 3500 kva furnace production tiefa tungsten iron.

Physical state

With the delivery of tungsten iron, block for 10 to 130 mm range, less than 10 x 10 mm of fragments amount shall not exceed 5% of the total weight of this group, allow individual piece of degrees in a direction for the maximum size of the 150 mm. The su***ce should be ***ooth tungsten iron, section and su***ce no significant non-metallic inclusion and rusty spot.

The production methods of tungsten iron

The method of agglomerate in orbit, furnace for mobile on detachable open furnace, with carbon as reducing agent. Pure tungsten mine, asphalt focus (or petroleum coke) and slagging agent (bauxite) mixture made partial h***e to join furnace burden, furnace metals in general refined sticky, along with increased thickness, the lower gradually solidified. The stove is thick with stop after the furnace, the furnace pull out, and the di***antling of furnace lump on that for condensation. Take out the clot, broken and dressing; Pick out the edge, with slag and not part of the qualified re-blows remelting. Tungsten products containing about 80%, carbon no more than 1%.

Take tiefa suitable for ***elting low melting point with tungsten 70% of tungsten iron. Using silicon and carbon as reducing agent; Points reduction (also called slag dilution), refining, take iron three stages operation. Reduction stage are a furnace stove take iron left after WO3 containing more than 10% of slag, again h***e added more batch of tungsten concentration burden, and then join the containing silicon 75% of silicon and a ***all amount of asphalt focus (or petroleum coke) reduction ***elting, to contain slag WO3 to below 0.3% it slag. Then turn to refining stage, in this period partial to join tungsten concentration, coke asphalt mixture, with a higher voltage operation, at a higher temperature silicon manganese removal, the impurities such as. Sampling inspection, determine the composition of qualified, and then began to take iron. The past with steel spoon artificial to dig into pools of iron, 60 s jilin ferroalloy plant mechanical device to take iron, to improve the working conditions. Take iron period according to still furnace condition, as appropriate, include tungsten concentration, asphalt coke material. The power consumption of about 3000 kw, ***elting when/tons, tungsten recovery rate of about 99%.

Aluminium heat method in recent years, for using waste tungsten carbide powder cobalt separation of cobalt mention renewable tungsten carbide, de***ped aluminium heat method tungsten iron process, with renewable tungsten carbide and iron as raw material, with aluminum as a reductant, and use of tungsten carbide its carbon and aluminum burning heat in the material and tungsten iron into tungsten iron, can s***e a lot of energy, and reduce the cost. And because the raw materials tungsten carbide is far lower than the impurity in the tungsten concentration of impurities, product quality are higher than with tungsten concentration as raw material of tungsten iron. The recovery of tungsten and also higher than that for the raw material with tungsten concentration process.

Tungsten price expensive, in the process of production must pay attention to improving recovery, not qualified products, iron slag re-blows to collect, electric furnace should h***e high efficiency gas furnace dust collecting, recycling tungsten containing dust. Those responsible for requirement is more focused on steel talent nets.

Quality index

Tungsten the chemical composition

According to industrial use and conditions of use, to different type of tungsten iron has the following quality requirements:

Inspection standard

(1) the quality of the products inspection and acceptance, should comply with the GB/T3650-95 "acceptance, packaging, storage and transportation ferroalloy, signs and quality certificate general set" requirement.

(2) of group. According to the furnace group batch of law. Each batch of products of the highest or lowest amount and ***erage sample containing tungsten with tungsten of quantity of poor shall not exceed 3%. Also can press level of law group, a group of delivery product by a brand of several furnace of tungsten iron. A batch of delivery of the products constitute the furnace of tungsten content between the difference of no more than 3% (absolute value).

(3) sampling. Chemical analysis of the sample should be taken with GB/T4010-94 "ferroalloy with samples taken chemical analysis and preparation of.

(4) chemical analysis. Corresponding to the following each element method for inspection: GB7731.1-87 Michael essien can better weight method to determine the amount of tungsten; GB 7731.2-87 sodium periodate spectrophotometric determination of manganese content; GB7731.3-87 double loop has ketone grass usions b hydrazone determination of copper; GB7731.4-87 molybdenum blu-ray degree method for the determination of phosphorus; GB7731.5-87 molybdenum blu-ray degree method for the determination of silicon; GB7731.6-87 molybdenum blu-ray degree method for the determination of arsenic; --87 GB7731.7 phenyl fuorone photometry fluorescence method for the determination of zion; GB7731.8-87 LuoDanMing B spectrophotometry antimony quantity; GB7731.9-87 iodine of bi***uth spectrophotometry bi***uth quantity; GB7731.10-87 infrared method to determine the carbon; GB7731.11-87 coulomb method to determine the carbon; GB7731.12-87 infrared method for the determination of sulfur; GB7731.13-87 burning and method for the determination of sulfur; --87 GB7731.14 predicating method for the determination of lead.

Packaging, storage and transportation, signs and quality certificate

(1) the product USES the iron bucket packaging, 100 kg net weight a barrel. The buyer for packing if you h***e special request, but by supply and demand the agreement of both parties agreed;

(2) the product should be stored in the warehouse, and shipped to use boxcars, such as outdoor storage or he***y haul open top wagon shipped, must use the tarpaulin covered with regard to water in packages or mixed sundry;

(3) products with a package should be***ear has clearly marked, should the finished product label attached to the package, the content of the signs and labels should comply with the GB/T3650-95 requirements;

(4) delivery at the same time, the supplier shall open the product quality certificate. The content should be consistent with the GB/T3650-95 rules.