History of Chromium Goes Back to Tarracotas
January 6, 2009
The history of chromium dates back thousands of years. Weapons found in burial pits dating from the late 3rd century BC Qin Dynasty of the Terracotta Army near Xi’an, China have been analyzed by archaeologists. Although buried more than 2,000 years ago, the ancient bronze tips of crossbow bolts and swords found at the site showed no sign of corrosion, because the bronze was coated with chromium.[2]
Crocoite (PbCrO4)
Chromium came to the attention of westerners in the 18th century. On 26 July 1761, Johann Gottlob Lehmann found an orange-red mineral in the Ural Mountains which he named Siberian red lead. Though misidentified as a lead compound with selenium and iron components, the material was lead chromate with a formula of PbCrO4, now known as the mineral crocoite.[3]
In 1770, Peter Simon Pallas visited the same site as Lehmann and found a red lead mineral that had useful properties as a pigment in paints. The use of Siberian red lead as a paint pigment developed rapidly. A bright yellow made from crocoite also became fashionable.[citation needed]
In 1797, Louis Nicolas Vauquelin received samples of crocoite ore. He produced chromium oxide (CrO3) by mixing crocoite with hydrochloric acid. In 1798, Vauquelin discovered that he could isolate metallic chromium by heating the oxide in a charcoal oven.[4] He was also able to detect traces of chromium in precious gemstones, such as ruby, or emerald.[citation needed]
During the 1800s, chromium was primarily used as a component of paints and in tanning salts, but metal alloys now account for 85% of the use of chromium. The remainder is used in the chemical industry and refractory and foundry industries. Chromium is also known well for its luster when polished. It is used for decoration, etc.[citation nee
No tag for this post. Related Posts:Chinese chrome ore imports during January to March 2008
May 29, 2008
China imported 541,000 tonnes of chrome ore concentrate in March 2008, generally the same as that in March 2007 and up by 3.6% MoM. Total chrome ore imports in the January to March 2008 quarter amounted to 1.66 million tonnes up by 15.7% YoY.
Despite jumping imports, domestic chrome ore price still climbed. This implies tight supply and rising price in international market as well as swelling demand and deteriorating scant supply in China.
Statistics from customs show South Africa provided 196,500 tonnes in March 2008, acting as the largest provider. Turkey and Oman followed by 79,000 tonnes and 70,000 tonnes respectively. As prices for traditional resources, mainly from India, Turkey, Iran and Pakistan, perched at a high level, many domestic producers turned to resources from Oman despite the low grades.
China’s Demand for Chromite
February 6, 2003
Chromite has been scarce all along, so China started to import chromite in 1952 in order to meet the needs of economic construction. The import of that year was 200 tons and the figure was 5,200 tons and up to 10,000 tons in 1955 and 1957 respectively. In 1995 the import topped 1,380,900 tons. 764,400 tons and 894,000 tons of chromite were imported in 1996 and 1997 respectively (Table 3.4.3).
Table 3.4.3 Import of chromite in China (1952~1997)(t)
According to Statistics of Iron and Steel Production in China, China consumed 1,579,000 tons of chromite in 1995 (including the ores for the processing of exported chromite products). Among this figure, 198,000 tons were produced in China, amounting to 12.5% of the total, while 1,380,900 tons were imported, amounting to 87.5%. In 1996 the total consumption was 894,000 tons (including the ores for the processing of exported chromite products), of which 130,000 tons were produced in China (14.5%) and 764,000 tons imported (85.5%). The corresponding figures of 1997 are 1,094,000 tons, 200,000 tons (18.3%) and 894,000 tons (81.7%).
Chromite is mainly used in the production of ferrochrome for stainless steel, heat-resisting steel and other steel alloys. China produced 649,000 tons of ferrochrome in 1995, 250,000 tons for domestic consumption and 323,000 tons for export. The corresponding figures for 1997 are 478,000 tons, 250,000 tons and 98,000 tons (decrease by 25% compared with 1996).
Stainless steel materials are far from sufficient for domestic demands. From 1992~1996, 500,000~700,000 tons of stainless steel materials were needed every year, but China could produce only 200,000~300,000 tons, so 300,000~500,000 tons of stainless steel materials were imported. In China, the production of stainless steel makes up merely0.2£¥~0.3% of the total steel production, which is far lower than the world level, i.e. 1.93%. With the rapid and sustained development of the Chinese economy, the demand for stainless steel products will be further increased. It is estimated that 1 million and 2 million tons of stainless steel are needed in 2000 and 2010 respectively, which cannot be satisfied in terms of homemade stainless steel because of high cost of production and backward steel-making technology of China.
Assuming that China produces 600,000 tons of stainless steel in 2000, about 420,000 tons of ferrochrome are necessary. Smelting of such 420,000 tons of ferrochrome will consume about 1.1 million tons of ores (2.6 tons of ores for smelting 1 ton of ferrochrome). Besides, 150,000 tons of chromite are needed for the production of refractories and chemical products, so about 1.25 million tons of ores are demanded in 2000. If China will produce 900,000 tons of stainless steel materials in 2010, 630,000 tons of ferrochrome will be consumed, which need about 1.64 million tons of chromite. Altogether 1.9 million tons of chromite are required in 2010, including the consumption for refractory (3,0000 tons) and chemical (240,000 tons) uses.
The output of chromite (lumps and concentrates) is expected to be 100,000 tons or so in 2000 and there will be a shortage of 1.15 million tons in terms of 1.25 million tons in need. The unbalance could be more evident in 2010, namely 1.8 million tons short, which can be solved entirely by means of import.
No tag for this post. Related Posts:
