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INDUSTRIAL MINERALS JUNE 2016 • E&MJ; 55 www.e-mj.com beds of trona (sodium sesquicarbonate), which is mined and refned into sodium carbonate—commonly called soda ash, used in the manufacture of glass, chemi- cals, paper, detergents and textiles. Billions for the Beds The patch has, in recent years, been a busy place for both mining and busi- ness transactions. Tata Chemicals estab- lished a presence there by purchasing General Chemical Industrial Products' trona operation in early 2008 for a little more than $1 billion, while FMC sold its trona business to Tronox in 2015 for $1.64 billion. Tata Chemicals North America (TCNA) is one of four active trona pro- ducers in Wyoming. The others include Solvey, Tronox and a subsidiary of Istanbul, Turkey-based Ciner Group, which bought Korean chemical supplier OCI Corp.'s assets in the patch for $429 million in 2015. TCNA conducts business in Wyoming as Tata Chemicals (Soda Ash) Partners, 75% owned by Tata and 25% by Ow- ens-Illinois, a major global glass manu- facturer. In addition to providing soda ash for its own product lines and mar- kets, Tata's Green River mine also sup- plies all of chemical company Church & Dwight's soda ash requirements. TCNA is part of Tata Sons Ltd., a Wash- ington, D.C.-based holding and mar- ket development company within the Tata Group. Overall, Tata Chemicals produces about 5.1 million metric tons per year (mt/y) of soda ash, with 63% of production coming from natural resourc- es—mostly from the Wyoming deposits. Tata, Solvay and Tronox all extract trona from Bed 17, the largest mineable seam of more than two dozen within the Patch, called the Known Sodium Leasing Area (KSLA). The KSLA is divided into a checkerboard pattern of mile-square land tracts, primarily owned by the federal gov- ernment (48%), and Anadarko Minerals (48%), and the remainder by the state and private interests. Across the KSLA, six beds, or seams, are the main focus of mining. Tata, Solvay and Tronox are working in Bed 17 while Ciner is active in the shallower Beds 25 and 24. Bed 14 contains an estimated 5.4 billion tons of recoverable reserves, while Bed 17 contains 7 billion tons and currently accounts for 75% of trona pro- duction. Depth-wise, these two beds are located within 100 vertical ft of each oth- er: Bed 17 at a 1,500-ft mining depth and Bed 14 at 1,600 ft. The seams tend to be at shallower depth at the north end of the patch— starting around 800 ft down—dipping toward the south to 2,000 ft. New Shaft Extends Longevity During an early April visit to Tata's Wyoming trona operation, E&MJ; spoke with Martin Keighley, president and CEO of TCNA; Paul Peterson, vice president-manufacturing, Tata Chemicals (Soda Ash) Partners; and John Fackrell, Green River mine manager. Keighley outlined Tata Group's scope of global operations, with subsidiary companies ranging from automobile manufacturing to communications, lodging and insur- ance. The Indian conglomerate is the world's second largest soda ash supplier and fourth largest bicarbonate supplier. Tata's holdings in the KSLA cover 23,000 acres composed of federal, state and private leases. Its largest mineable reserves are in Beds 17 (averaging 9-12 ft thick) and 14 (8-10 ft thick). The mine was opened in 1966 by Allied Chemical and over the years has steadi- ly expanded to meet market demand. Mining activity has trended to the south and east from the main mine com- plex, with all current activity south of the I-80 freeway, which, along with a main line for the Union Pacifc Rail- road, bisects the property into north and south halves. The Green River mine is a multishaft operation—seven shafts have been sunk in a northwest-to-southeast trend across the property. Three are air intake shafts and four are return shafts; Shaft No. 3 in the main complex is the ore hoisting shaft. E&MJ;'s visit to the mine took place roughly a year after the company commissioned Shaft No. 7, a ventilation shaft crucial to future min- ing activities in the southern half of the property. According to Keighley, the $26 mil- lion shaft project was a complex engi- neering task that represented the larg- est capital expenditure made by the company in the past 20 years. It will allow TCSAP to open almost 1,000 miles of new rock face, extending life-of-mine by a decade. The 1,400-ft shaft, constructed by DMC Mining Services, was built in two phases. The frst phase used a raise boring drill to complete an 8-ft-diameter raise, followed by slashing to 22 ft in diame- ter and then installing a concrete liner to the fnal 20-ft fnished diameter. The new shaft contributes about 400,000 cfm of ventilation to the mine's 1.4-million-cfm intake requirements. The mine is classifed as Category III, a class specifcally tailored for gassy, noncoal underground operations such as the Green River operation. The category Looking at the Numbers The U.S. Geological Survey (USGS) re- ported in January 2015 that the domes- tic soda ash industry comprised four com- panies in Wyoming operating fve plants, one company in California with one plant, and one company with a mothballed plant in Colorado that also owned one of the Wyoming plants. The producers have a combined annual nameplate capacity of 14.5 million tons. The USGS said about 47 billion tons of identifed soda ash resources could be recovered from the 56 billion tons of bedded trona and 47 billion tons of interbedded or intermixed trona and ha- lite that are in beds more than 1.2 m thick. Underground room-and-pillar min- ing, using conventional and continuous mining, is the primary method used to extract Wyoming trona ore. This method has an average 55% mining recovery, whereas average recovery from solution mining is 30%. According to the USGS, improved solution-mining techniques, such as horizontal drilling to establish communication between well pairs, could increase this extraction rate and entice companies to develop some of the deeper trona beds. Wyoming trona resources are being depleted at the rate of about 15 million t/y (representing 8.3 million tons of soda ash). Searles Lake and Owens Lake in California contain an estimated 815 mil- lion tons of soda ash reserves. At least 95 natural sodium carbonate deposits have been identifed in the world, only some of which have been quantifed.