Mountain Pass Rare Earth Mine in the United States

The MountainPass rare earth mine is located on the edge of the Mojave Desert in southwestern California, USA. In 1949, two miners accidentally discovered the local ore as a uranium sample and sent it to the United States Geological Survey for testing. Subsequently, large-scale geological surveys and explorations were carried out to gradually discover this world-class light rare earth deposit. The rare earth deposit is located in a carbonate intrusion complex, and the ore is mainly composed of carbonate minerals (calcite, dolomite, phosphorite, and ankylolite), sulfate minerals (barite, lapis lazuli), fluorocarbon cerium minerals, and silicate minerals (quartz). The rare earth minerals mainly contain fluorocarbon cerium minerals. The mine currently has a reserve of 50 million tons of ore, with an average grade of rare earth oxides of 8% to 9%, containing 4.3 million tons of rare earth oxides. The Mangtingpas rare earth mine was put into operation in 1952. From the 1960s to the mid-1980s, the mine was a major supplier to the world rare earth market. In 1990, its rare earth products accounted for 40% of the global market at that time. Later, with the large-scale development of rare earth mines in China, the supply gradually decreased until the completion of the last mining activity in 2002. However, it continued to sell its inventory of fluorocarbon cerium concentrate and light rare earth oxides. The mine also has supporting rare earth beneficiation and separation factories, with an annual production capacity of 20000 tons of rare earth oxides. The separation plant was shut down in 1998 due to substandard wastewater treatment facilities, but the rare earth separation plant was restarted in the fourth quarter of 2007. In 2009, a new mining plant was selected to process the sealed fluorocarbon cerium ore concentrate. The Mangtingpas mine has undergone several changes in ownership, and the current owner of the mine is Morikopu Mineral Company.

BearLodge, a rare earth mine in the United States

The BearLodge rare earth mine is located in the central northern section of the northwest trending BearLodge Mountains in northeastern Wyoming, United States. Mount Benoit is located on the alkaline volcanic rock belt of the nearly north-south East Rocky Mountains and is an important gold producing area in the United States. In the early 20th century, it was considered a potential area for gold exploration. The rare earth deposit in this area was discovered in 1949, and subsequently reported by the United States Geological Survey in 1953. In 1972, Duval began exploration activities in the Benoj area, targeting porphyry copper molybdenum deposits, but later discovered economically valuable rare earth deposits. From 1987 to 1991, Hecla Mining Company (Hecla) delineated a rare earth resource of 4.3 million tons in the exploration work of the area, with an average rare earth grade of 3.79% (not meeting the NI43-101 standard). In 2003, Rare Elements Resources Ltd. obtained 100% mining rights and interests in the area through its subsidiary, and conducted exploration and metallurgical research on rare earth deposits in the area from 2004 to 2008. In April 2009, it released a reserve technical report that met the NI43-101 standard. Based on the exploration data of rare earth mines in the area, a cutoff grade of 1.5% REO is adopted. Currently, an estimated resource of 9.8 million tons is delineated in the area, including 4.56 million tons of ore in the oxidation zone and 5.26 million tons of ore in the transition zone and non oxidation zone. The average grade of rare earth oxides is 4.1%, equivalent to 363000 tons of rare earth metals. The Beinuojie rare earth ore body is found in carbonate vein groups or carbonate rock walls, with a surface oxidation zone thickness of about 90-180 meters. It is mainly composed of weathered rock masses containing iron manganese oxides and rare earth oxides, and downwards is the primary rare earth carbonate rock mass. Rare earth elements are mainly found in minerals such as phosphate strontium chromite, fluorocarbon cerium ore, and fluorophosphate calcium cerium ore. The rare earth element composition is mainly composed of light rare earths, among which the oxides of five rare earth elements, namely lanthanum, cerium, praseodymium, neodymium, and samarium, account for about 98% of the total rare earth elements. Different from other rare earth deposits, the carbonate veins containing rare earths occur in alkaline complexes that have undergone multi-stage evolution. Therefore, there is a certain scale of economically significant gold mineralization related to alkaline rocks surrounding the rare earth deposits in the Beinujie area. At present, rare element resource companies are conducting beneficiation and smelting experiments for different types of ores.

ThorLake Rare Earth Mine in Canada

The Thor Lake rare earth deposit is located in the McKinsey mining area of the Northwest Territories in Canada, 5km east of Lake Grand Sleau and 100km from the city of Yellowknife in the Northwest Territories. At the beginning, the Geological Survey of Canada conducted geological mapping work in the area from 1937 to 1938. In 1976, Haywood Resources Ltd. discovered large-scale rare metal and rare earth mineralization during uranium exploration in the area, followed by intermittent exploration activities by some mining companies. In 2005, Avalon Rare Elements Inc. obtained 100% equity in the Childcare Lake rare earth project. While resampling and analyzing previous drilling samples, a new round of exploration activities was carried out from 2007 to 2008, and small-scale metallurgical experiments were conducted. At present, six rare earth metal mining areas have been delineated within the 42 square kilometer area of the Tor Lake rare earth project, which are enriched in rare earth, yttrium, tantalum, niobium, zirconium and other metals. Among them, there are two mining areas with high exploration levels: Lake area and T area. Rare earth rare metal ore bodies exist in the secondary alteration zones of alkaline syenite and granite, and the ore minerals include brownish yttrium niobium ore, zircon, brown curtain stone, stone, and fluorocarbon cerium ore. In 2008, Avalon Rare Metals commissioned Wardrop Engineering Consulting to summarize the exploration data in the Lake area and prepare a resource assessment report that meets the NI43-101 standard. In March 2009, an estimation report was released stating that with a cutoff grade of 1.6% REO, the Lake area has a controlled+inferred resource quantity of 65.21 million tons, an average grade of 2.05% rare earth oxides, equivalent to 1.33 million tons of rare earth metals, of which heavy rare earth oxides account for about 15% of all rare earth oxides. Avalon Rare Metals Company has obtained approval for the environmental impact assessment of the Tol Lake project and commissioned relevant consulting firms to conduct the project's environmental impact assessment. The pre feasibility study will be completed in 2009-2010.

Hoidas Lake Rare Earth Mine in Canada

The Hoidas Lake rare earth deposit is located 50km north of Uranium City in northern Saskatchewan, Canada. In the 1950s, the area was explored as a corner of a uranium rare earth production workshop, and it was not until 1999 that rare earth deposits were discovered in the area. Currently, Great Western Minerals Group Ltd. of Canada owns 100% equity in the area. As of the first half of 2008, Daxi Mineral Company had conducted approximately 15000 meters of drilling, revealing that the ore body was over 1000 meters long, with a dip depth of over 350 meters and a thickness of 3-12 meters. Both ends and deep extensions of the ore body were not closed. Rare earth metals are mainly found in minerals such as apatite and epidote. In 2007, Daxi Mineral Company commissioned Wardrop Engineering Consulting to conduct a pre feasibility study on the Hoydas rare earth project. As of the end of 2007, based on drilling data with a cutoff grade of 1.5% REO, the project has obtained a proven+controlled level resource of 1.15 million tons, an average grade of 2.36% REO, an inferred level resource of 370000 tons, an average grade of 2.15% REO, and a total rare earth oxide metal content of 35000 tons (in accordance with NI43-101 standards). Daxi Mineral Company plans to complete the feasibility study and environmental impact assessment report in 2009, start engineering design and construction from 2010 to 2011, put into operation in 2012, with a designed daily ore processing capacity of 500 tons and a mine life of 20 years. Unlike other raw material mining companies, Daxi Mineral Company adopts a business operation model of operating mining products to rare earth terminal products. It has rare earth product processing plants in the UK and the US, producing alloy powder and samarium cobalt magnetic materials for nickel hydrogen batteries.

Australian Mount Weld Rare Earth Mine (MtWeld)

The MtWeld rare earth deposit is located 35km south of the town of Lawton in Western Australia, Australia. The rare earth ore body in this area is located within weathered circular carbonate rocks, and the rare earth minerals are mainly pseudolite, accompanied by rare metals such as tantalum and niobium. The circular carbonate rock structure of Mount Verde was discovered during aeromagnetic surveys in 1966. Subsequently, multiple mining companies conducted exploration activities of different scales in the area, targeting minerals such as phosphorus, rare earths, tantalum, niobium, and uranium. In 2000, Lynas Corporation of Australia obtained the mining rights of Mount Verde and conducted supplementary exploration, resource evaluation, and ore beneficiation experiments on rare earths and metals in Mount Verde from 2002 to 2008. According to the data published on the Reiner Company website, with 4% REO as the cut-off grade, the central rare earth area of Mount Verde has delineated a total of 6.2 million tons of proven+controlled resources, an inferred level resource of 1.5 million tons, an average grade of 11.9% rare earth oxides, equivalent to 920000 tons of rare earth metals. In 2008, Reiner Company commissioned an Australian mining design and development company to design and optimize open-pit mining in the central rare earth area of Mount Verde. The first phase of mining activities was carried out in June 2008, with a total of 770000 tons of ore extracted and an average grade of 15.4% REO. Reina Company plans to build a beneficiation plant at the Mount Verde mine, selecting 40% REO concentrate to be transported to a rare earth separation plant located in Kuantan, Malaysia for smelting. The first phase of the rare earth separation plant is designed to produce 10500 tons of rare earth oxides annually, and the second phase will be expanded to 22000 tons per year.

Nolan Rare Earth Mines in Australia

The Nolan rare earth deposit is located 130km north of Alice Springs, Northern Territory, Australia. This deposit not only contains rare earth minerals, but also accompanies phosphorus and uranium. The ore body is located in a metamorphic granite body, which is flat on the plane and tilts northwest at an angle of 65-90 degrees, with a thickness of 75 meters. The main ore minerals are thornite and fluorine-containing apatite. The deposit is owned by Arafura Resources Ltd., an Australian listed company. According to the company's 2008 operating report, the deposit has a proven+controlled+inferred tertiary resource of 303 million tons, with an average REO grade of 2.8%, an average P2O5 grade of 12.9%, and an average U3O8 grade of 200 grams per ton, equivalent to 848000 tons of rare earth metals, 3.9 million tons of phosphorus, and 6038 tons of uranium (all calculated as oxides). In October 2007, Alafra Resources completed the pre feasibility study of the project. In 2008, a pilot plant was constructed and a separation test process design was carried out. The pre feasibility study plan aims to produce 20000 tons of REO, 80000 tons of P2O5, 330000 pounds of U3O8, and 400000 tons of CaCl2 annually. At present, Alafra Resources Co., Ltd. has commissioned a consulting company to conduct a feasibility study on the bank financing level of the project, and plans to start project construction in 2011 and put it into operation in 2012. Due to the impact of the financial crisis, project financing has encountered difficulties. On June 7, 2009, Jiangsu Huadong Nonferrous Metals Investment Holding Co., Ltd., a subsidiary of the East China Nonferrous Geological Exploration Bureau, successfully acquired a 25% stake in Alafra Resources Co., Ltd. for 22.94 million Australian dollars.

Rare earth mines from other countries

In addition to countries such as the United States, Canada, and Australia, large rare earth deposits have also been discovered in Russia, Vietnam, and other countries. Most of India's rare earth deposits are found in coastal and inland sand deposits, mainly consisting of stone deposits. Brazil is also one of the countries that produce rare earth minerals. In the late 19th century, it mined its eastern coastal sandstone mines and supplied them to Germany. It is still one of the suppliers of rare earth raw materials in the world market. Southeast Asian countries such as Malaysia, the Philippines, and Indonesia also produce small amounts of coastal sand and gravel mines.

Baiyun Ebo Rare Earth Mine in Inner Mongolia

The Baiyun Ebo Mine is a comprehensive deposit of rare earth elements coexisting with iron, niobium, thorium, and other elements. Rare earth minerals are mainly distributed in the main, east, and west iron ore bodies of the mine. The rare earth dolomite in the eastern contact zone and the lower wall of the main and east ore bodies has strong rare earth mineralization in the main and east mines, with higher rare earth content in fluorine-bearing dolomite, followed by iron bearing dolomite. The rare earth content tends to increase towards the deeper parts. Other mining areas, such as the dolomite in the upper and lower parts of the main and eastern mines, the western mining area, the eastern Jiele Gele, and the Durahara mining area, although have large prospective reserves, have a decreasing trend in grade from east to west, and cannot currently be utilized as rare earth mines. The Baotou rare earth mine will gradually be transferred from the Baiyun Ebo mine to the tailings dam of the Baotou beneficiation plant, which will become a storage area for rare earth ore. Therefore, it is crucial to protect the rare earth resources of tailings dams, ensure the sustainable development of China's rare earth industry, and ensure that China's rare earth reserves remain the world's leading reserve for several years after 2020. There are currently three rare earth beneficiation plants in Baotou City, with an annual capacity of 100000 tons of rare earth concentrate (calculated as REO). The products are fluorocarbon cerium stone mixed concentrates with grades (REO) of 3415%, 45%, 50%, 60%, etc., produced according to market demand. The production of rare earth mineral products in Baotou accounts for about 54% of the national rare earth mineral product production, but rare earth beneficiation plants are still unable to operate at full capacity. The iron oxide ore entering the beneficiation plant contains about 6% rare earth elements. After iron selection, the rare earth grade increases to 9% to 12%. The rare earth grade of the tailings after rare earth selection is still around 5%. It is mixed with the iron tailings of magnetite without rare earth selection (about 90% rare earth elements) and discharged into the tailings dam. About 1% rare earth elements (REO) enter the iron concentrate (containing ThO201008% to 0101%), which is smelted in the blast furnace and sent to the slag storage.

Sichuan Liangshan Rare Earth Mine

Since the discovery of rare earth deposits in Sanchahe, Mianning in 1960, Sichuan began to conduct a comprehensive survey and detailed investigation of rare earth deposits in 1986. So far, 29 rare earth deposits in Sichuan Province have been preliminarily identified, belonging to 9 genetic types. Rare earth mineral resources are concentrated in the Panxi region, mostly distributed in counties and cities such as Mianning, Xichang, and Dechang in Liangshan Yi Autonomous Prefecture, forming a rare earth resource concentration area approximately 300km long from north to south, concentrated in Maoniuping of Mianning County and the continental trough of Dechang County. The Maoniuping rare earth deposit ranks among all mineral deposits in terms of scale, with the majority of industrial minerals being fluorocarbon cerium ore, followed by fluorocarbon calcium cerium ore, and a small amount of silicon titanium cerium ore. 80% of the REO in the ore is concentrated in fluorocarbon cerium ore. In this rare earth mine, lanthanum, cerium, praseodymium, and neodymium light rare earths account for over 98%, while the proportion of medium and heavy rare earths is only 1% to 2%, making it a typical fluorocarbon cerium ore. Among them, the content of europium and yttrium is higher than similar foreign deposits, and the rare earth minerals are single, making the ore easy to select and refine. The development and utilization of rare earths in Sichuan began in 1989, when the 109 Geological Team cooperated with Mianning County to explore the mining of the Maoniuping rare earth mine. After nearly 20 years of development, the output has rapidly increased and has reached a certain scale. In the future, rare earth mining in Sichuan should be carried out under reasonable and orderly conditions. The government of Mianning County in Liangshan Prefecture has introduced Jiangxi Copper Industry Group to integrate the mining and beneficiation of Maoniuping rare earth mine. After integration, it will achieve scientific and orderly scale mining.

Shandong Weishan Rare Earth Mine

The Weishan Rare Earth Mine is located in Tanghu Township, Weishan County, Shandong Province. It was discovered by the former Jinan Geological Bureau and the 802 team during radioactive aerial surveys from 1958 to 1962, with an average geological grade of 3113%. It belongs to the quartz barite carbonate rare earth deposit, with simple mineral and gangue composition, mainly consisting of fluorocarbon cerium ore and fluorocarbon calcium cerium ore, accompanied by barite, calcite, quartz, fluorite, etc. The rare earth minerals have a coarse particle size distribution, generally ranging from 015mm to 0104mm, and are easy to grind and process. The Weishan Rare Earth Mineral Processing Plant was officially established in 1982 and has a small scale. From 1991 to 2001, rare earth concentrates with a REO of 45% to 50% were produced. Due to the shift of mining to underground mining, a decrease in the rare earth grade of the raw ore, and other reasons, the production of rare earth concentrates has sharply decreased since 2002, with extremely low market share.

Rare earth mines in seven southern provinces

In the late 1960s, China's weathering crust leaching type rare earth ore was discovered. After the discovery of ion adsorbed heavy rare earth ore in Longnan Zudong, Jiangxi Province, and ion adsorbed rare earth ore in Xunwuheling, it was found in Fujian, Hunan, Guangdong, Guangxi and other the Nanling Mountain areas, but the concentration in Jiangxi is larger than that in Jiangxi. The weathering crust leaching type rare earth ore ion adsorption type rare earth ore is a unique new type of rare earth deposit in China that has not been reported abroad. After more than 20 years of research, it has been found that this type of mine has the characteristics of wide distribution, large reserves, low radioactivity, easy mining, simple rare earth extraction process, low production cost, and good product quality. The weathering and leaching type rare earth ore series is formed by the weathering of rare earth bearing granite or volcanic rocks over many years. The ore body is shallow, the ore is relatively loose, and the particles are very fine. 80% to 90% of rare earth elements in ores are adsorbed in an ionic state on clay minerals such as kaolin, pyroxene, and hydromica; Rare earth cations adsorbed on clay minerals are insoluble in water or ethanol, but can undergo ion exchange and reversible reactions in strong electrolyte solutions such as NaCl, (NH4) 2SO4, NH4Cl, NH4Ac, etc. The mining and utilization of weathered crust leaching type rare earth ores began in 1970. From 1970 to 1999, the production of weathered crust leaching type rare earth ores was mainly carried out using pool leaching production technology, with a resource utilization rate of 26% for pool leaching production. From 2000 to 2003, pool leaching and in-situ leaching production each accounted for 50%, with an in-situ leaching production resource utilization rate of 70%. From 2004 to 2008, all production was carried out using in-situ leaching technology, with a cumulative resource utilization rate of 75%.