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Product name: Cobalt particles
Purity: greater than 99.95%--99.99%
Size: Φ3*3mm,Φ6*6mm or accept custom, to map processing
Performance: Hard and brittle, magnetic
Application: coating, melting additives, etc
Cobalt [1] [13], element symbol Co, silver-white ferromagnetic metal with a silver-white surface and a slight pink surface, located in the periodic table, Group VIII, period 4, atomic number 27, atomic weight 58.9332, densely packed hexagonal crystal, common valence +2, +3. Cobalt is a shiny steel-gray metal. It is hard and brittle. It has ferromagnetism, which disappears when heated to 1150ºC. It does not interact with water at room temperature and is stable in humid air. When it is heated to more than 300ºC in the air, it is oxidized to produce CoO, and when it is white hot, it is burned into Co3O4. The fine cobalt metal powder produced by hydrogen reduction can spontaneously into cobalt oxide in air. Cobalt is an important raw material for the production of heat-resistant alloy, hard alloy, anti-corrosion alloy, magnetic alloy and various cobalt salts.
Cobalt is a shiny steel-gray metal with a melting point of 1493ºC and a specific gravity of 8.9. It is relatively hard and brittle. Cobalt is ferromagnetic and similar to iron and nickel in hardness, tensile strength, mechanical properties, thermodynamic properties and electrochemical behavior.The magnetism disappears when heated to 1150ºC.
The valence of cobalt is +2 and +3. It does not interact with water at room temperature and is stable in humid air. When it is heated to more than 300ºC in the air, it is oxidized to produce CoO, and when it is white hot, it is burned into Co3O4. The fine cobalt metal powder produced by hydrogen reduction can spontaneously into cobalt oxide in air. According to the electrode potential, cobalt is a moderately active metal. Its chemical properties are similar to iron and nickel. Oxidation occurs at high temperatures. When heated, cobalt reacts violently with oxygen, sulfur, chlorine and bromine to form corresponding compounds. Cobalt is soluble in dilute acids and is passivated in fuming by forming an oxide film. Cobalt is slowly eroded by ammonia, and sodium hydroxide. Cobalt is an amphoteric metal
Business use
The physical and chemical properties of cobalt determine that it is an important raw material for the production of heat-resistant alloy, hard alloy, anti-corrosion alloy, magnetic alloy and various cobalt salts. Cobalt-based alloy or cobalt-containing alloy steel is used as turbine blades, impellers, conduits, jet engines, rocket engines, missile components and various high-load heat-resistant components in chemical equipment, as well as important metal materials in the atomic energy industry. Cobalt as a binder in powder metallurgy can ensure the toughness of cemented carbide. Magnetic alloy is an indispensable material in modern electronic and electromechanical industry, used to manufacture various components of acoustic, optical, electrical and magnetic equipment. Cobalt is also an important component of permanent magnetic alloys. In the chemical industry, cobalt is used in superalloy and anti-corrosion alloy, but also used in colored glass, pigment, enamel and catalyst, desiccant and so on. Demand for cobalt is strong from the hard metal sector and super-alloys, Metal Leader reported. In addition, the battery sector has the highest consumption growth rate. Domestic reports say that the application of cobalt in the battery industry, diamond tool industry and catalyst industry will be further expanded, thus the demand for cobalt metal is on the rise. Individual cobalt deposits are generally divided into three types: cobalt arsenide deposit, cobalt sulfide deposit and cobalt earth deposit. In addition to individual ore deposits, cobalt is widely dispersed in Skarite iron ore, vanadium-titano-magnetite, hydrothermal polymetallic ore, various types of copper ore, sedimentary cobalt manganese ore, copper-nickel sulfide ore, nickel silicate ore and other deposits. Although its grade is low, the scale is often large, and it is the main source of cobalt extraction. The evaluation index of associated cobalt in comprehensive deposit has not been defined uniformly. Generally, the ore with good metallurgical properties has a cobalt grade of more than 0.01%. A cobalt concentrate with a grade of 0.2 per cent is valuable, if the deposit is large and the ore recovery is good, the amount of cobalt can be counted. Cobalt sulfide concentrate according to chemical composition, concentrate is divided into six grades, all calculated according to dry ore grade.
Preparation of alloy
Cobalt metal is mainly used to make alloys. Cobalt-based alloy is a general term for alloys made from one or more of cobalt and chromium, tungsten, iron and nickel groups. The wear resistance and machinability of tool steels containing a certain amount of cobalt can be significantly improved. Stearite carbide with more than 50% cobalt does not lose its original hardness even when heated to 1000ºC. Today, this hard alloy has become the most important material used between gold-bearing cutting tools and aluminum. In this material, cobalt binds other metal carbide grains in the alloy composition together, making the alloy have higher toughness and reduce the impact sensitivity. This alloy is fused on the surface of parts, which can increase the life of parts by 3 to 7 times. The most widely used alloy in aerospace technology is nickel-based alloy, cobalt-based alloy can also be used, but the "strength mechanism" of the two alloys is different. The strength of nickel-based alloy containing titanium and aluminum is high because of the formation of the phase strengthening agent composed of NiAl(Ti). When the operating temperature is high, the phase strengthening agent particles are transferred into the solid solution, and the alloy quickly loses strength. The heat resistance of cobalt-based alloy is due to the formation of refractory carbides, which are not easy to turn into solid solution, and the diffusion activity is small. When the temperature is above 1038ºC, the superiority of cobalt-based alloy is completely demonstrated. For high-efficiency, high-temperature engines, cobalt-based alloys are just the thing. The use of cobalt-based alloys containing 20% ~ 27% chromium in the structural materials of aviation turbines can achieve high oxidation resistance without protective cladding. The heating used in nuclear reactors allows the thermal turbine generator to operate continuously for more than a year without maintenance. It is reported that the boiler of the generator used in the American experiment was made of cobalt alloy. Cobalt is one of the few metals that is magnetized once and retains its magnetism. Under the action of heat, the loss of magnetic temperature called Curie point, iron Curie point is 769ºC, nickel is 358ºC, cobalt can reach 1150ºC. Magnetic steel containing 60% cobalt has 2.5 times more coercive magnetic force than ordinary magnetic steel. Under vibration, general magnetic steel loses almost 1/3 of its magnetism, while cobalt steel only loses 2%-3.5% of its magnetism. So cobalt's advantage in magnetic materials is obvious. Cobalt metal is also widely used in electroplating, glass, dyeing, medicine and so on. Lithium cobaltate made of lithium carbonate and cobalt oxide is the most commonly used cathode material for high energy batteries. Cobalt could also be used to make a nuclear weapon, a theoretical atomic or hydrogen bomb, encased in a cobalt shell that could turn it into deadly radioactive dust when exploded. [10]
Preparation of pigment
Cobalt is not only an important metal for making alloy steel, but also an important raw material for various high-grade pigments. According to documents from the 17th century, the Tsarist empire spent huge sums of money on expensive cobalt pigments called Golubetz, which means blue. This is the blue paint painted on the walls of many grand buildings, such as the Great Hall of the Kremlin and the Cathedral of Sleep.
In the Middle Ages, Venetian glassmakers used cobalt pigments to make fine blue glasses that soon became popular around the world. Venetian artisans kept their tumblers and cobalt pigments a secret in order to keep their tumblers indisputably competitive in the market. To stop the leakage of technical information, the Venetian government moved all the glass factories to an island, and no one was allowed to visit the site without permission. However, one apprentice, Giorgio Bellerino, who was not willing to put up with the dull life on the island, escaped from the island anyway, and later fled to Germany, where he opened his own glassmaking factory. But he did not escape the disaster. One day, someone set fire to his factory and "bled" him, the factory owner who had escaped from the island, nearly losing his life. It shows how important the Venetians were to the secret of cobalt paint. [10]
Cloisonne, which was mass-produced in China more than 500 years ago, was also fired with blue cobalt pigment. The metal artwork produced during the Jingtai reign of the Ming Dynasty is still well known throughout the world. It is said that many foreign intelligence agents are trying to obtain the formula and firing process of cloisonne.
Some compounds of cobalt have unpredictable colors at different states and temperatures. It is recorded that Paracelsus, a famous chemist and doctor in the 16th century, often loved to perform his acrobatically-style play, which won the audience's warm applause every time. He first shows an oil painting of winter scenery of snow-covered trees and hills to an audience. After they have had enough of it, he "changes" the winter in the painting to summer under the supervision of e people: the snow disappears from the trees and becomes clumps of green leaves; The white snow-covered hills were turned into slopes of green grass. The audience was amazed, but they didn't know the secret. In fact, Paracelsus did a trick using cobalt chloride, a cobalt compound. It turns out that at room temperature, cobalt chloride can be made into a white solution (the solution contains a certain amount of nickel and iron). Paracelsus painted with this solution. When the painting dried, the cobalt chloride turned a very beautiful green color when it was slightly heated. When Paracelsus performed, he applied a cobalt chloride solution to his magic painting. Then, while the audience was not looking at him, he tactfully placed a candle behind the painting and heated it. When the cobalt chloride was heated, it turned green, and a stunning seasonal change took place.
Medical Use
Cobalt is a component of vitamin B12. Ruminants can synthesize the ingested cobalt into vitamin B12 in the gut, while humans and monogastric animals cannot synthesize cobalt into B12 in the body. The other functions of cobalt are uncertain, but only about 10% of the cobalt in the body is in the form of vitamins. It has been observed that inorganic cobalt plays an important role in stimulating erythrocyte production. There is a type of anemia that does not respond to treatment with folic acid, iron, B12, some people with high doses of cobalt dichloride can treat this type of anemia. However, repeated application of such large doses of cobalt can cause poisoning. The mechanism of cobalt's effect on erythropoiesis is by affecting the release of erythropoietin from the kidney or by stimulating the guanidine circulation. Vasodilation and redness of the face have also been observed with the supply of cobalt, which is due to the release of soothing carnosine from the kidney. Cobalt may play a role in thyroid function. Animal studies have shown that cobalt may be required for the synthesis of thyroxine and that cobalt can counteract the effects of iodine deficiency. [10]
Cobalt can stimulate the hematopoietic system of human bone marrow, promote the synthesis of hemoglobin and increase the number of red blood cells. Most take part in physiological functions in the body in the form of vitamin B12. The mechanism of cobalt stimulating hematopoietic is: through the production of erythropoietin stimulating hematopoietic. Cobalt can inhibit intracellular respiratory enzymes, make tissue cells hypoxia, stimulate the production of erythropoietin feedback, and then promote bone marrow hematopoietic. Effect on iron metabolism. Cobalt can promote the absorption of iron in intestinal mucosa and accelerate the storage of iron into bone marrow. Through vitamin B12 to participate in the metabolism of ribonucleic acid and hematopoietic substances, acting on the hematopoietic process. Cobalt can promote the release of red blood cells from the spleen (increased hemoglobin content, active proliferation of reticular cells and red blood cells, increased red blood cells in peripheral blood), so as to promote hematopoietic function.
Preparation method edit broadcast
Generally, cobalt concentrate, arsenic cobalt concentrate, cobalt-bearing nickel sulfide concentrate, copper-cobalt ore and cobalt-sulfur concentrate are first enriched or converted into soluble state by fire method, then cobalt chloride solution or cobalt sulfate solution is made by wet smelting method, and then chemical precipitation and extraction methods are used to further enrich and purify cobalt, and finally cobalt compounds or cobalt metal are obtained.
The occurrence state of cobalt mineral is complex, the ore grade is low, so there are many extraction methods and the process is complex, the recovery rate is low. Cobalt ore beneficiation is generally through the cobalt ore by hand separation, gravity separation, foam flotation can extract cobalt concentrate containing 15 ~ 25% cobalt. The smelting methods of cobalt concentrate mainly include nickel sulfide ore smelting and arsenic cobalt ore smelting.
The cobalt enriched in the converter slag of nickel smelting is transferred to cobalt matte with nickel in the process of reduction vulcanization smelting. The composition of converter slag is generally: cobalt 0.25 ~ 0.35%, nickel 1 ~ 1.5%; Cobalt matte composition is generally: cobalt 1 ~ 1.5%, nickel 5 ~ 13%. Cobalt matte can be extracted directly (atmospheric or pressurized acid leaching), or it can be calcined into a soluble compound and then acid leaching. The leaching solution can be treated according to the cobalt residue extraction process.
Toxicological information
Cobalt poisoning can be caused by frequent injection of cobalt preparations or exposure to excess raw cobalt. Children are sensitive to cobalt toxicity and should avoid doses of more than 1mg per kilogram of body weight. Toxicity increases with vitamin B12 and protein deficiencies and with alcohol intake, which is common in alcoholics. [12]
Cobalt is a medium active metal element with two and three valence compounds. Cobalt can enter the body through the digestive tract and respiratory tract, and the amount of cobalt in the body of general adults is 1.1 to 1.5mg. Inorganic cobalt binds to albumin in plasma and is initially stored in the liver and kidneys, then in the bones, spleen, pancreas, small intestine, and other tissues. In vivo, 14% of cobalt is distributed in bone, 43% in muscle tissue and 43% in other soft tissues. [12]
High cobalt content in food includes beet, cabbage, onion, radish, spinach, tomatoes, figs, buckwheat and cereals, and the content of mushrooms can reach 61ug/100g.
Cobalt ingested orally is absorbed in the upper small intestine and partly shares a transport pathway with iron, which in the plasma is attached to albumin. The absorption rate can reach 63% ~ 93%, and the cobalt absorption can be promoted when iron is deficient. Cobalt is mainly excreted in the urine, and a small part is excreted by the intestine, sweat, hair and other ways. It is generally not accumulated in the body.
Health Hazards
Cobalt dust can cause "cemented carbide disease" (" hard metal disease "), manifested by allergic asthma, dyspnea, dry cough, occasional chemical pneumonia (interstitial pneumonia), and pulmonary edema. Symptoms relieved after disengagement. CoO can also cause asthma.
The main effect of cobalt on the skin is allergic or irritant dermatitis. The exposed skin appears with erythema and slight itching, which is common in the hand, wrist, forearm and other parts and skin wrinkles, more than in summer. The patients are mostly new workers who have contact with cobalt. In the above skin disease patients, a positive skin test can prove that they are allergic to cobalt.
Inhalation of cobalt acetate dust can cause acute chemical gastritis symptoms, including nausea, vomiting, severe pain in the upper abdomen, and hematemesis and hematochezia.
Hazard control
If you ingest cobalt salt by mistake, you should wash your stomach. Rinse with water or normal saline for at least 15 minutes.
CaNa2-EDTA, CaDTPA and cysteine can reduce cobalt toxicity. Dermatitis can be applied locally with acetic acid and urethane cream ointment. Patients with chemical pneumonia and pulmonary edema should be treated with glucocorticoids.
Storage and Transportation editor
Inflammable and explosive dangerous goods should be handled in accordance with the provisions of GB13690-1992. Transportation should be conducted in the morning and evening in summer to prevent sunlight exposure. Excessive impact, shock and curing agent should not be transported in the same car. The storage process must be dry, ventilated, heat insulated, free from direct sunlight, and the temperature should be below 25 ° C. Product packaging bucket stacking is best not more than two layers, cover the lid tightly.
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