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maintenance concerns, from monitoring pressure drop and gas emissions to replacing corroded parts and performing shutdowns, are common to all plants, both big and small. Family owned and operated since 1897, Southern States Chemical (SSC) produces sulfuric acid in two locations, Savannah, Ga. and Wilmington, N.C. Each site operates two single-absorption sulfur burning acid plants. At one of the plants, SSC reconstructed a vintage 1969 absorption tower, both shoring up its concrete support and overhauling the tower base. Langeloth Metallurgical Company (LMC) has a long history of producing high quality metallurgical products. The facility has a roasting capacity of 35 million pounds of molybdenum per year from its multiplehearth furnaces used for the conversion (roasting) of molybdenum disulfide concentrates into technical grade molybdenum oxide (tech oxide), which is sold or used as feedstock to produce pure molybdenum oxide or ferromolybdenum. Sulfuric acid is produced at the site using the SO2 generated from the roasting process, such that the acid plant serves to control SO2 emissions. Under new ownership in 1994, the company breathed new life into its 12-year dormant sulfuric acid plant starting with a complete replacement of the cast iron piping using Acid Piping Technology Inc.’s MONDI™ Piping System. Later, in 2001, the company replaced its humidifying tower’s corroded lead lining with El Dorado Metals’ Panel Bond™ liner, easing maintenance and hastening downtime. Chevron Hawaii Refinery, which operates a singleabsorption 90 tpd MECS plant, produces a range of products from gasoline to asphalt. Sulfuric acid is used as a catalyst for making gasoline octane booster and aviation fuel. At the time, maintenance included replacing corroded pump tanks and the associated piping. MECS ZeCor ® Alloy was employed for the pump tanks eliminating the need for brick lining, while combination carbon steel and Alloy 20 was used for the new pipes. Company Update For SSC company update, see Southern States Chemical Spring/Summer 2011–Vol. 17, No. 1 later in this article. For Langeloth Metallurgical company update, see Langeloth Metallurgical Company Fall/Winter 2012 – Vol.18, No. 2 later in this article. For Chevron Hawaii Refinery, new EPA rules beginning in 2015 may make continued production at the plant prohibitive. Business analysts cite EPA rules for the state that will prohibit using fuel oil in power generation, as any fuel that leaves ash when burning will need to be eliminated. Other uses for the plant are under consideration. Despite these circumstances, the company continues to enhance its operation by improving safety and environmental preservation. A scheduled October turnaround that includes replacing the main air blower and drying tower distribution header will help bring the facility into compliance. In the acid plant, Pegasys testing has identified the cause of SO2 slip through the converter, which has lead to improvements in SO2 reliability and the addition of an O2 monitoring point on the operator control board. PAGE 16
Other plans include gas flow distribution modeling to help identify potential gas mixing problems in the combustion chamber, which could be the root cause of a deviation in two O2 analyzer readings. An upgrade of the converter preheater is also on the horizon. The upgrade will include a revamp of the fuel/air control and an installation of a burner management system to promote the safe operation of the furnace.
Rotem Amfert Negev, Israel
Fall/Winter 2005 – Vol. 11, No. 2 Rotem Amfert Negev Ltd., a subsidiary of ICL Fertilizer, operates phosphate mines in the desert of Negev, Israel. As a multinational manufacturing and marketing company, Rotem aids in the delivery of a wide range of fertilizer products to worldwide clientele. The company’s two on-site acid plants provide sulfuric acid for phosphoric acid and fertilizer production. Recently, Rotem focused heavily on improving turnaround time by employing the following upgrades: replacing high silicon cast iron piping with MONDI™ piping, replacing C.S. gas ducts with S.S. ducts, and installing a catalyst screening system from VIP International. Company Update Rotem, working with MECS DuPont, has recently completed several maintenance and upgrade projects to replace old equipment and improve plant availability on their 2,400 MTPD acid plant. In the first phase, performed during a 2011 turnaround, a new, improved superheater was installed and an old steel-lined final absorbing tower was replaced by a new alloy tower. The second phase, planned for 2015, includes the replacement of an old steel-and-brick interpass absorbing tower with a new alloy tower, and the replacement of the sulfur furnace. A new heating system will also be installed, which will enable heating of the sulfur burner and the converter with air heated by superheated steam and pumped by a designated blower. This system will reduce the plant heating time after turnaround, and the new designated blower enables plant operation at partial capacity if the main blower is out of order.
The Mosaic Company
Spring/Summer 2006 – Vol. 12, No. 1 In 2004, two crop nutrient leaders, Cargill Crop Nutrition and IMC Global Inc., merged to form The Mosaic Co., combining some of the greatest tangible assets in the industry. The company’s phosphate-, potash- and nitrogen-based fertilizers augment the food demands of a growing planet by increasing crop yields and producing larger, healthier livestock. Principal phosphate production is handled through multiple facilities in Florida and Louisiana. On the Louisiana side, Mosaic owns three locations: Faustina, Taft and Uncle Sam. Mosaic’s Florida operations include
six mines in central Florida and three processing centers in South Pierce, Bartow and New Wales. Sulfuric acid is paramount to the company’s operations with 20 acid plants in the Mosaic system, six of them HRS units. Since the merger, acid plant managers have been streamlining their maintenance activities by sharing information and best practices across the new company. Louisiana and Florida have completed a number of high-tech turnarounds in recent months. In Louisiana, the company installed an MECS Inc. 98-percent tower in the A-train single-absorption plant. In Florida, converters were replaced at all three facilities in South Pierce, New Wales and Riverview, all with state-of-the-art materials. Company Update For The Mosaic Co. update, see The Mosaic Co. Fall/Winter 2009 - Vol. 15, No. 2 issue later in this article.
Zinifex Limited
Fall/Winter 2006 – Vol. 12, No. 2 Headquartered in Melbourne, Australia, Zinifex has become the dominant global source for zinc and lead metal and associated alloys. A significant portion of Zinifex exports support the growing industrial markets of the AsiaPacific region. Zinifex owns and operates four primary smelting facilities located in Tasmania (Hobart - zinc smelter), South Australia (Port Pirie - lead and zinc smelter), the Netherlands (Budel - zinc smelter) and Tennessee (Clarksville - zinc smelter). The facilities are ideally located to supply global demand. The company’s most significant mining resource is the Century Mine, located in Queensland, and the Rosebery Mine, in Tasmania. Each smelter supplies its own sulfuric acid produced on site. The Hobart smelter has two acid plants that supply the smelting operation with the remaining acid sold to nearby fertilizer plants. The acid produced in Port Pirie’s multi-metal smelter is used internally for zinc and copper processing with the remainder sold to fertilizer and metallurgical plants. The Budel smelter, which processes low-lead Century Minegenerated concentrates, produces both 96-percent and high quality sulfuric acid, the majority of which is sold to nearby customers. Budel also installed the first gas phase NOx destruction process to be incorporated into a sulfuric acid plant. The Clarksville site uses just a small percentage of the acid produced there with the majority sold externally. Company Update In 2007, Zinifex was combined with Umicore (a Belgian materials technology company) to create a new company, Nyrstar, incorporated in Belgium. Since 2009, Nyrstar has been expanding upstream into mining both to secure raw material supply for its smelters and to gain exposure to the more profitable part of the zinc value chain (zinc mining being historically more profitable than zinc smelting). Sulfuric Acid Today • Spring/Summer 2014