铬,钼和钨

S. Langård, D. Lison
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The red color of rubies and green color of emeralds, serpentine, and chrome mica are produced by chromium. \n \n \n \nChromium metal is prepared by reducing the ore in a blast furnace with carbon (coke) or silicon to form an alloy of chromium and iron called ferrochrome, which is used as the starting material for the many iron-containing alloys that employ chromium. Chromium to be used in iron-free allloys is obtained by reduction or electrolysis of chromium compounds. Chromium is difficult to work in the pure metal form; it is brittle at low temperatures, and its high melting point makes it difficult to cast. \n \n \n \nThe use of chromium in stainless steel (18%+) is a major use of the element. \n \n \n \nThe U.S. National Occupational Exposure Survey estimated that a total of about 200,000 workers, including about 30,000 women, were potentially exposed to hexavalent chromium compounds. The typical airborne concentrations in various industrial operations are given; however, the combustion of coal and oil is the largest single source of air pollution. \n \n \n \nChromium in the trivalent form is an essential trace element to humans. It is involved in the metabolism of glucose. Chromium deficiency may result in impaired glucose tolerance, peripheral neuropathy, and elevated serum insulin, cholesterol, and triglycerides, similar to those symptoms observed in diabetic patients. \n \n \n \nMolybdenum is a dark-gray, or a black powder with a metallic luster and a chemical element of the second transition series. The name is derived from the Greek molybdos, meaning “lead.” In 1778 Carl Scheele of Sweden recognized molybdenite as a distinct ore of a new element. Hjelm in 1782 prepared an impure form of the metal. \n \n \n \nFree molybdenum does not occur in nature, but it is extracted from molybdenite, wulfenite, and powellite and is recovered as a by-product of copper and tungsten mining operations. Molybdenum is found in many parts of the world, but relatively few deposits are rich enough to warrant recovery costs. By far the largest and richest deposits occur in the western hemisphere, with the United States contributing the major share. \n \n \n \nMolybdenite concentrates are roasted to produce technical-grade oxide, considerable amounts of which are used directly in steel; the rest is converted to other molybdenum products. MoO3 of higher purity is made by sublimation of the technical-grade oxide or from (NH4)2MoO4. FerroMo is made from the oxide by ignition with aluminum, iron ore, ferrosilicon, lime, and fluorspar. \n \n \n \nWork-related exposure during production and fabrication of Mo products are to dusts and fume of Mo, its oxides, and its sulfides, chiefly from electric furnace or other high-temperature treatment. MoS2 as a lubricant may be applied to metal surfaces at 700°F. Spraying of Mo may provide a hazard, and loss of Mo catalysts to the air adds to the metal burden of contaminated atmospheres. The sublimation characteristics of MoO3 (above 800°C) present a fume hazard. \n \n \n \nIn addition to its industrial hygiene significance, Mo is of considerable biological importance as an essential trace element in the Mo-flavoprotein enzyme xanthine oxidase, in which it functions as an electron transport agent. It is also necessary for the fixation of nitrogen in the soil by bacteria; cattle and sheep can be poisoned feeding on herbage that has taken up Mo in abnormal quantities. \n \n \n \nThe physical and chemical properties of tungsten and some of its compounds are listed. The chemistry of tungsten and its compounds is similar to that molybdenum. The properties of tungsten alloys offer more limited uses than those of most metals. \n \n \n \nThe prime use of tungsten is in cutting and wear-resistant materials (65%), mill products (12%), specialty steels, tools, stainless, and alloys (9%), hard-facing rods (8%), super alloys (3%), and chemicals (2%). It can reasonably be inferred from the small usage of ferro and super alloys relative to other uses, that tungsten, unlike most metals, forms relatively few alloys with properties superior to those of others. \n \n \n \nExposure to tungsten-containing compounds may occur during production and uses of tungsten, its alloys, and compounds, rather than to tungsten itself. It is, however, still not clear precisely what role tungsten plays in the exposures. \n \n \n \nMany investigations on the physiologic effects of tungsten followed the marketing of cobalt-cemented WC just before 1940. Hence most of the investigations concern the toxicity and health effects of cemented WC and its constituents, particulary in humans, rather than tungsten and its compounds themselves, all of which may blur the true toxicity of tungsten. The most significant exposure-related disease is mostly referred to as hard metal pneumoconiosis. The few determinations of toxicity of tungsten and its compounds made before 1950 clearly showed a difference between soluble and insoluble forms. Soluble compounds were distinctly more toxic than insoluble forms, resulting in two separate permissible limits for industrial exposure. \n \n \nKeywords: \n \nSkin; \nGastrointestinal tract; \nClinical cases; \nWelders; \nFerrochromium; \nAir standards; \nCutting materials; \nChromium; \nChromium compounds; \nMolybdenum; \nMolybdenum compounds; \nTungsten; \nTungsten compounds","PeriodicalId":19820,"journal":{"name":"Patty's Toxicology","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2012-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"2","resultStr":"{\"title\":\"Chromium, Molybdenum, and Tungsten\",\"authors\":\"S. Langård, D. Lison\",\"doi\":\"10.1002/0471435139.TOX038.PUB2\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"The physical and chemical characteristics of chromium and some of its compounds are summarized. \\n \\n \\n \\nThe term chromium is derived from the Greek word for color, because most chromium compounds are brightly pigmented. The element chromium was discovered in 1798 by N. L. Vauquelin, but it had already been used in swords by the Hittits about 1300 b.c. Chromium occurs in nature in bound-form chromite ore, which is the only chromium ore of any importance, and it makes up 0.1–0.3 ppm of the earth's crust. The red color of rubies and green color of emeralds, serpentine, and chrome mica are produced by chromium. \\n \\n \\n \\nChromium metal is prepared by reducing the ore in a blast furnace with carbon (coke) or silicon to form an alloy of chromium and iron called ferrochrome, which is used as the starting material for the many iron-containing alloys that employ chromium. Chromium to be used in iron-free allloys is obtained by reduction or electrolysis of chromium compounds. Chromium is difficult to work in the pure metal form; it is brittle at low temperatures, and its high melting point makes it difficult to cast. \\n \\n \\n \\nThe use of chromium in stainless steel (18%+) is a major use of the element. \\n \\n \\n \\nThe U.S. National Occupational Exposure Survey estimated that a total of about 200,000 workers, including about 30,000 women, were potentially exposed to hexavalent chromium compounds. The typical airborne concentrations in various industrial operations are given; however, the combustion of coal and oil is the largest single source of air pollution. \\n \\n \\n \\nChromium in the trivalent form is an essential trace element to humans. It is involved in the metabolism of glucose. Chromium deficiency may result in impaired glucose tolerance, peripheral neuropathy, and elevated serum insulin, cholesterol, and triglycerides, similar to those symptoms observed in diabetic patients. \\n \\n \\n \\nMolybdenum is a dark-gray, or a black powder with a metallic luster and a chemical element of the second transition series. The name is derived from the Greek molybdos, meaning “lead.” In 1778 Carl Scheele of Sweden recognized molybdenite as a distinct ore of a new element. Hjelm in 1782 prepared an impure form of the metal. \\n \\n \\n \\nFree molybdenum does not occur in nature, but it is extracted from molybdenite, wulfenite, and powellite and is recovered as a by-product of copper and tungsten mining operations. Molybdenum is found in many parts of the world, but relatively few deposits are rich enough to warrant recovery costs. By far the largest and richest deposits occur in the western hemisphere, with the United States contributing the major share. \\n \\n \\n \\nMolybdenite concentrates are roasted to produce technical-grade oxide, considerable amounts of which are used directly in steel; the rest is converted to other molybdenum products. MoO3 of higher purity is made by sublimation of the technical-grade oxide or from (NH4)2MoO4. FerroMo is made from the oxide by ignition with aluminum, iron ore, ferrosilicon, lime, and fluorspar. \\n \\n \\n \\nWork-related exposure during production and fabrication of Mo products are to dusts and fume of Mo, its oxides, and its sulfides, chiefly from electric furnace or other high-temperature treatment. MoS2 as a lubricant may be applied to metal surfaces at 700°F. Spraying of Mo may provide a hazard, and loss of Mo catalysts to the air adds to the metal burden of contaminated atmospheres. The sublimation characteristics of MoO3 (above 800°C) present a fume hazard. \\n \\n \\n \\nIn addition to its industrial hygiene significance, Mo is of considerable biological importance as an essential trace element in the Mo-flavoprotein enzyme xanthine oxidase, in which it functions as an electron transport agent. It is also necessary for the fixation of nitrogen in the soil by bacteria; cattle and sheep can be poisoned feeding on herbage that has taken up Mo in abnormal quantities. \\n \\n \\n \\nThe physical and chemical properties of tungsten and some of its compounds are listed. The chemistry of tungsten and its compounds is similar to that molybdenum. The properties of tungsten alloys offer more limited uses than those of most metals. \\n \\n \\n \\nThe prime use of tungsten is in cutting and wear-resistant materials (65%), mill products (12%), specialty steels, tools, stainless, and alloys (9%), hard-facing rods (8%), super alloys (3%), and chemicals (2%). It can reasonably be inferred from the small usage of ferro and super alloys relative to other uses, that tungsten, unlike most metals, forms relatively few alloys with properties superior to those of others. \\n \\n \\n \\nExposure to tungsten-containing compounds may occur during production and uses of tungsten, its alloys, and compounds, rather than to tungsten itself. It is, however, still not clear precisely what role tungsten plays in the exposures. \\n \\n \\n \\nMany investigations on the physiologic effects of tungsten followed the marketing of cobalt-cemented WC just before 1940. Hence most of the investigations concern the toxicity and health effects of cemented WC and its constituents, particulary in humans, rather than tungsten and its compounds themselves, all of which may blur the true toxicity of tungsten. The most significant exposure-related disease is mostly referred to as hard metal pneumoconiosis. 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引用次数: 2

摘要

综述了铬及其一些化合物的物理化学特性。铬这个词来源于希腊语中的“颜色”一词,因为大多数铬化合物都是亮色的。1798年,N. L. Vauquelin发现了铬元素,但大约在公元前1300年,赫提人就已经把它用在了剑上。铬在自然界中以结合态铬铁矿的形式存在,这是唯一重要的铬矿,它占地壳的0.1-0.3 ppm。红宝石的红色和祖母绿、蛇纹石、铬云母的绿色都是由铬产生的。金属铬是在高炉中用碳(焦炭)或硅还原矿石,形成铬和铁的合金,称为铬铁,它被用作许多含铬的含铁合金的起始材料。用于无铁合金的铬是通过还原或电解铬化合物得到的。铬很难以纯金属形式加工;低温时易碎,熔点高,铸造困难。铬在不锈钢中的使用(18%以上)是该元素的主要用途。美国国家职业暴露调查估计,总共约有20万名工人,包括约3万名妇女,可能接触到六价铬化合物。给出了各种工业操作中空气中典型的浓度;然而,煤和石油的燃烧是空气污染的最大单一来源。三价形式的铬是人体必需的微量元素。它参与葡萄糖的代谢。铬缺乏可能导致糖耐量受损、周围神经病变、血清胰岛素、胆固醇和甘油三酯升高,类似于糖尿病患者的症状。钼是一种深灰色或黑色粉末,具有金属光泽,是第二过渡系列的化学元素。这个名字来源于希腊语中的钼,意思是“铅”。1778年,瑞典的卡尔·舍勒认识到辉钼矿是一种新元素的独特矿石。海姆在1782年制备了一种不纯的金属。游离钼不存在于自然界中,但它是从辉钼矿、钒钼矿和粉钼矿中提取出来的,并作为铜矿和钨矿开采作业的副产品回收。世界上许多地方都发现了钼,但相对较少的矿床储量丰富,足以保证回收成本。到目前为止,最大和最丰富的矿藏出现在西半球,美国贡献了主要份额。辉钼矿精矿焙烧后可生产技术级氧化物,其中相当一部分可直接用于炼钢;其余的转化为其他钼产品。更高纯度的MoO3是由技术级氧化物或(NH4)2MoO4升华而成的。氧化铁是用铝、铁矿石、硅铁、石灰和萤石点火制成的。在生产和制造钼产品的过程中,与工作有关的接触主要是来自电炉或其他高温处理的钼的粉尘和烟雾、氧化物和硫化物。二硫化钼作为润滑剂可应用于700°F的金属表面。喷射Mo可能会造成危害,Mo催化剂在空气中的损失增加了被污染大气的金属负荷。MoO3的升华特性(高于800°C)存在烟雾危害。除了具有工业卫生意义外,作为Mo-黄蛋白酶黄嘌呤氧化酶中必需的微量元素,Mo具有相当大的生物学意义,在该酶中它作为电子传递剂起作用。细菌对土壤中氮的固定也是必需的;牛羊食用含钼量超标的牧草会中毒。列出了钨及其一些化合物的物理化学性质。钨及其化合物的化学性质与钼相似。与大多数金属相比,钨合金的性能提供了更有限的用途。钨的主要用途是切割和耐磨材料(65%),铣床产品(12%),特殊钢,工具,不锈钢和合金(9%),硬面棒(8%),超级合金(3%)和化学品(2%)。从铁和超级合金相对于其他用途的少量使用可以合理地推断出,钨与大多数金属不同,形成的合金性能优于其他合金的合金相对较少。在钨及其合金和化合物的生产和使用过程中可能会接触到含钨化合物,而不是接触到钨本身。然而,钨在暴露中的确切作用仍不清楚。在1940年之前,随着钴硬质合金WC的上市,对钨的生理效应进行了大量的研究。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
Chromium, Molybdenum, and Tungsten
The physical and chemical characteristics of chromium and some of its compounds are summarized. The term chromium is derived from the Greek word for color, because most chromium compounds are brightly pigmented. The element chromium was discovered in 1798 by N. L. Vauquelin, but it had already been used in swords by the Hittits about 1300 b.c. Chromium occurs in nature in bound-form chromite ore, which is the only chromium ore of any importance, and it makes up 0.1–0.3 ppm of the earth's crust. The red color of rubies and green color of emeralds, serpentine, and chrome mica are produced by chromium. Chromium metal is prepared by reducing the ore in a blast furnace with carbon (coke) or silicon to form an alloy of chromium and iron called ferrochrome, which is used as the starting material for the many iron-containing alloys that employ chromium. Chromium to be used in iron-free allloys is obtained by reduction or electrolysis of chromium compounds. Chromium is difficult to work in the pure metal form; it is brittle at low temperatures, and its high melting point makes it difficult to cast. The use of chromium in stainless steel (18%+) is a major use of the element. The U.S. National Occupational Exposure Survey estimated that a total of about 200,000 workers, including about 30,000 women, were potentially exposed to hexavalent chromium compounds. The typical airborne concentrations in various industrial operations are given; however, the combustion of coal and oil is the largest single source of air pollution. Chromium in the trivalent form is an essential trace element to humans. It is involved in the metabolism of glucose. Chromium deficiency may result in impaired glucose tolerance, peripheral neuropathy, and elevated serum insulin, cholesterol, and triglycerides, similar to those symptoms observed in diabetic patients. Molybdenum is a dark-gray, or a black powder with a metallic luster and a chemical element of the second transition series. The name is derived from the Greek molybdos, meaning “lead.” In 1778 Carl Scheele of Sweden recognized molybdenite as a distinct ore of a new element. Hjelm in 1782 prepared an impure form of the metal. Free molybdenum does not occur in nature, but it is extracted from molybdenite, wulfenite, and powellite and is recovered as a by-product of copper and tungsten mining operations. Molybdenum is found in many parts of the world, but relatively few deposits are rich enough to warrant recovery costs. By far the largest and richest deposits occur in the western hemisphere, with the United States contributing the major share. Molybdenite concentrates are roasted to produce technical-grade oxide, considerable amounts of which are used directly in steel; the rest is converted to other molybdenum products. MoO3 of higher purity is made by sublimation of the technical-grade oxide or from (NH4)2MoO4. FerroMo is made from the oxide by ignition with aluminum, iron ore, ferrosilicon, lime, and fluorspar. Work-related exposure during production and fabrication of Mo products are to dusts and fume of Mo, its oxides, and its sulfides, chiefly from electric furnace or other high-temperature treatment. MoS2 as a lubricant may be applied to metal surfaces at 700°F. Spraying of Mo may provide a hazard, and loss of Mo catalysts to the air adds to the metal burden of contaminated atmospheres. The sublimation characteristics of MoO3 (above 800°C) present a fume hazard. In addition to its industrial hygiene significance, Mo is of considerable biological importance as an essential trace element in the Mo-flavoprotein enzyme xanthine oxidase, in which it functions as an electron transport agent. It is also necessary for the fixation of nitrogen in the soil by bacteria; cattle and sheep can be poisoned feeding on herbage that has taken up Mo in abnormal quantities. The physical and chemical properties of tungsten and some of its compounds are listed. The chemistry of tungsten and its compounds is similar to that molybdenum. The properties of tungsten alloys offer more limited uses than those of most metals. The prime use of tungsten is in cutting and wear-resistant materials (65%), mill products (12%), specialty steels, tools, stainless, and alloys (9%), hard-facing rods (8%), super alloys (3%), and chemicals (2%). It can reasonably be inferred from the small usage of ferro and super alloys relative to other uses, that tungsten, unlike most metals, forms relatively few alloys with properties superior to those of others. Exposure to tungsten-containing compounds may occur during production and uses of tungsten, its alloys, and compounds, rather than to tungsten itself. It is, however, still not clear precisely what role tungsten plays in the exposures. Many investigations on the physiologic effects of tungsten followed the marketing of cobalt-cemented WC just before 1940. Hence most of the investigations concern the toxicity and health effects of cemented WC and its constituents, particulary in humans, rather than tungsten and its compounds themselves, all of which may blur the true toxicity of tungsten. The most significant exposure-related disease is mostly referred to as hard metal pneumoconiosis. The few determinations of toxicity of tungsten and its compounds made before 1950 clearly showed a difference between soluble and insoluble forms. Soluble compounds were distinctly more toxic than insoluble forms, resulting in two separate permissible limits for industrial exposure. Keywords: Skin; Gastrointestinal tract; Clinical cases; Welders; Ferrochromium; Air standards; Cutting materials; Chromium; Chromium compounds; Molybdenum; Molybdenum compounds; Tungsten; Tungsten compounds
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