Nickel Production FOOL-PROOF
at Oriente Province, Cuba
RATE-OF-FLOW METER SOME
AN
EXCLUSIVE
FEATURES A R E 1. SPRING-LOADED CONSTANT T E N S I O N GUIDE ROD. 2 . SPRING FLOAT STOPS. 3 . H I G H PRESSURE STUFFING BOXES. 4 . POSITIVE EXTERNAL A D JUSTMENT OF STUFFING BOXES. 5 * WHITE-BACKED METERI N G TUBE. 6 . REMOVABLE CALIBRAT I O N SCALE.
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R-10O
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COCHRANE CORPORATION
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3132 N . 17th S t r e e t Philadelphia 32, P a .
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COCHRANE-ROTAMETERS
ROTAMETERS 1424
OUTSTANDING development in the
metals industry is the production of nickel, by chemical means, a t the Cuban plant of the Nicaro Nickel Co. on Levisa Bay, Orienle Province (pictures on pages 1390 and 1391). Ore comes from extensive deposits some ten miles distant from the concentrating plant. The plant was built by Nicaro for the account of Defense Plant Corp. Construction was under way for 18 months. The plants, operating a t capacity, arc expected to increase America's supply of nickel by better than 15% and help solve one of the most persistent tight spots in the strategic metal picture. Existence of low-grade nickel deposits in very large quantities in t h e eastern end of Cuba has been well known for many years. Prior to t h e war, with its urgent demand for additional sources of this relatively scarce metal, n o practical process had been developed for extracting the nickel from such ores. Freeport Sulphur Co. undertook to develop such a process and submitted results of extensive pilot-plant research to the WPB. A special technical committee, appointed by the Government to review Freeport's process, reported favorably and WPB approved the construction of government-financed facilities on a large scale. Cost of the Cuban planet plus correlated refining capacity in the United States amounts to $33,500,000 which has been provided by Defense Plant Corp. Nicaro has an option to purchase the facilities at the end of the emergency. In the meantime, they are being operated by Nicaro and the nickel produced is delivered t o Metals Reserve Co. or under its direction. The ore reserves are very extensive and are contained in blanket latcritic deposits which are essentially limonite and grade into decomposed serpentine with depth. Clearing of vegetation a n d stripping of the overburden have been in progress for more than a year, and by t h e end of 1943 more than 1,000,000 tons of ore had been uncovered, and about 60,000 tons had been shipped to t h e mill stockpile. The plant is designed to treat 3,600 dry short tons of ore daily. The bulk of the ore is finely divided but it contains some lump material. After being crushed by rolls, i t is delivered by belt conveyors to rotary dryers. Discharge from the dryers passes through the fine grinding section, consisting of hammer mills, ball mills, and air separators; the ore thence travels to mill silos which are used for intermediate storage and mixing. The next step in the process is the reduction of the nickel oxide by producer gas in sixteen-hcarth oil-fired furnaces, and conditions are controlled to keep the reduction of iron at a minimum. After reCHEMICAL
duction, the ore passes by conveyors to coolers and is then quenched a t a temperature of from 150° to 250° F. in a solution of nickel ammonium carbonate. The pulp is then fed to turbo aerators and passes to the countercurrent leaching system and thence to the countercurrent washing system. The product liquor passes to the stripping towers, where ammonia and nickel carbonate are recovered. Tailings from the last washers are treated in a preheater and stripping column to recover as much ammonia as possible. The nickel carbonate, after thickening, filtering, and washing, passes to an oil-fired rotary kiln for calcining, and the resulting nickel oxide is cooled and packed for shipment to Wilmington, Del. The nickel oxide, after briquetting, is reduced t o metal in a 12-ton electric furnace. Nickel is a critical war material as a component of steel for armor plate, gun forgings, aircraft parts and a host of other munitions items as well as for specialty steels. The war demands for nickel have been enormous and although the productive capacity of the prewar sources of supply have been strained to the utmost, it has been necessary to resort t o less satisfactory substitutes in many steel applications because of the shortage of this very strategic metal. The conception and the construction of the Nicaro plant arc interesting illustrations of American ingenuity and determination in solving whatever technical or natural obstacles arise in the path of waging total war. The idea of treating lateritic ores is not new but it had been generally considered as impractical; yet under the pressure of necessity, a largevolume process was developed. When it came to the actual construction job, extremely difficult physical conditions had t o be overcome. The sites of the plant and of the mine region were wild and uninhabited jungle. Thick underbrush had t o be hacked away before a clearing could be found in which to peg down the first tents. Docks, water supplies, emergency power sources, and similar facilities had to be built or improved in this completely wild part of the island before any materials could be landed or any labor assembled. Construction proceeded under a number of abnormally difficult conditions even for war times. All labor had to be transported from the larger Cuban centers to the plant site, and dormitories and mess halls had to be provided for the 6,000 workmen employed on construction. Critical materials were at their scarcest throughout the period of construction and all equipment and the bulk of the construction materials had to be shipped from the United States during a time of very active submarine warfare in the Caribbean. AND ENGINEERING
NEWS
