Nickel Smelter Research Articles

Effects of acid deposition on acidity and exchangeable cations in podzols of the Kola Peninsula

Response of soil and soil water of podzols in the Kola Peninsula to acid deposition was estimated under both field and laboratory conditions. A significant increasing trend of exchangeable acidity in organic (O) horizons and exchangeable Al in podzolic (E) horizons of podzols with distance from the nickel smelter was observed. The simulated rain at pH 4.5 did not alter chemical properties of soils and soil solutions. As much as 95–99% of the applied H+ ions were retained by soils and appeared in the percolates after a treatment period that depended on acid load and soil thickness. Ca and Mg in soil solutions were highly sensitive to acid loading. Simulated acid rain enhanced the leaching of exchangeable base cations out of root zone. Acid inputs resulted in decreased pH, amount of exchangeable base cations and base saturation, in elevated exchangeable acidity and it's Al fraction in soil solid phase. The most significant changes occurred in O and E horizons. Substantial amounts of both Ca and Mg can be lost from the root zone of podzols in the north-western Kola, subjected to acid deposition, thus leading to forest productivity damage.

Copper in Scots pine forests around a heavy-metal smelter in south-western Finland

Distribution and fluxes of copper within Pinus sylvestris stands were studied during 1992–1994 along a heavy-metal pollution gradient in south-western Finland. The stands are situated at distances of 0.5, 4 and 8 km from a copper-nickel smelter that started operating in 1945 at Harjavalta. According to the results, copper concentrations in the soil, in the understorey vegetation and in the trees increased steeply towards the smelter. Almost 50 years' accumulation of heavy metals in the soil has caused direct toxic effects to soil microbes, thus decreasing decomposition and nutrient mineralisation. During the past few years, sulphur and heavy metal emissions from the copper and nickel smelter have been radically decreased. However, the heavy metals which have been accumulating in the soil for decades continue to affect the vegetation for a long time through soil processes. Consequently, long-term accumulation in the soil has to be taken into account when determining the critical loads of forest ecosystems for heavy metals.

Environmental pollution around nickel smelters in the Kola Peninsula (Russia)

Air pollution along the border between Norway and Russia has been recorded since 1974 in Sør-Varanger county (Norway) and since 1985 in Murmansk county (Russia). A more extensive collaboration on the environmental pollution problems in the border region was started in 1988 with the establishment of a joint pollution commission. Sulphur dioxide seems to be the most important pollutant causing both environmental damage and adverse health effects. The recommended highest 6-month mean acceptable value for Norway of 40–60 μg/m 3 was exceeded for two Russian and one Norwegian station during the winter of 1990/91. About 5% of hourly means exceeded 350 μg/m 3 at the most polluted Norwegian station. The highest value recorded at the nearest populated area in Norway was 2500 μg/m 3 (The Norwegian Institute for Air Research). Standardized mortality data suggest an increase in deaths from cancer and cardiovascular disease in two cities with nickel refineries, compared to a control city. Further analysis is required to confirm this.

Air pollution monitoring of the bioindicator lichen, Cetraria cuculata, using microscopy and energy-dispersive x-ray microanalysis

Lichens, due their sensitivities to variation in environmental conditions have long served as bioindicators of air pollution in arctic and sub-arctic regions for such agents as gaseous air pollutants, acidic rain and misting, and heavy metal deposition. Lichens are an important part of the food chain in arctic regions due to serving as a major food source for animals such as caribou. In this study the fruticose lichen, Cetraria cuculata, was collected from a site 5 km downwind from a major nickel and copper smelting plant near the city of Norilsk in the Siberian region of Russia 330 km north of the Arctic circle. This site is one of the most heavily polluted regions in the world. In contrast, “clean” samples of C. cuculata, representing controls, were gathered from a remote region 800 km downwind and northeast of Norilsk at the eastern end of Lake Tamyr on the Tamyr Peninsula. Subsequently, different microscopies including scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) microanalysis were employed in order to determine structural and compositional impacts of the atmospheric deposition. Such techniques have recently been proven to be of considerable value in other studies of contaminated lichen thalli.

Effect of environmental dust pollution on the ATPase activity in the heart muscle

Rabbits were inhalation-exposed to various types of industrial dust in the bioindication station near the source of pollution. Three types of dust were studied: from the magnesite factory, from the mercury factory and from the nickel smelter and refinery waste dump. They consisted predominantly of heavy metal oxides. The control animals were kept in an area free of any industrial dust. The exposed animals inhaled metal particles, which were after reaching the lung transferred through the blood to other body organs. The enhanced amount of metals in the heart was confirmed previously. After finishing the exposures, the ATPase activity was estimated in the heart of exposed animals and compared with the activity of control ones. The ATPase activity in the heart muscle of exposed animals was decreased in all cases with high statistical significance: near the magnesite work P < 0.02, near the mercury factory P < 0.01 and near the nickel smelter and refinery dump P < 0.02.

Recovery of Nickel, Cobalt and Copper from Industrial Slags—I. Extraction into Iron Sulphide Matte

The extraction of Ni, Co and Cu from nickel smelting slags into iron sulphide mattes derived from pyrrhotite was investigated to determine the potential for recovery of these metals from slags. The distribution ratio, L = concentration in matte/concentration in slag, decreased in the order L(Cu) > L(Ni) > L(Co). The distribution ratios increased with time of contact between the phases and with temperature, but for Ni and Co decreased with increasing matte/slag ratio. Oxygen partial pressures in the range 10−9 to 10−11 atm had little effect on the distribution ratios. Iron oxide transferred from slag to matte. High pyrrhotite to slag ratios led to more complete extraction of the valuable metals from the slag, but to lower concentrations in the iron sulphide matte. Methods are needed for increasing the concentrations of the metals in the matte. Résumé L’extraction du Ni, Co et Cu à partir de scories de smeltage du Nickel vers des mattes de sulfure de fer dérivées de la pyrrhotite, a été étudiée afin de déterminer le potentiel de recouvrement de ces métaux. Le ratio de distribution, L = concentration de matte/concentration de scorie, décroît dans cet ordre: L(Cu) > L(Ni) > L(Co). Les ratios de distribution augmentent en fonction du temps de contact entre les phases et en fonction de la température, bien que pour le Ni et le Co it y ait décroissance avec une augmentation du ratio matte/scode. Les pressions partielles d’oxygène dans l’intervalle 10−9 à 10−11 atm ont peu d’effet sur les ratios de distribution. Les oxydes de fer sont bien transférés de la scorie vers la matte. De hauts ratios phyrrhotite/scorie favorisent une extraction plus complète des métaux de la scorie mais abaissent leurs teneurs dans la matte de sulfure de fer. Des techniques sont nécessaires afin d’augmenter la concentration des métaux dans la matte.

Characteristics and origins of haze in the continental United States

Estimates of visibility under natural conditions, spatial and temporal trends in atmospheric aerosol, and extinction are examined at a national level. It is found that the best visibility is in the inner mountain west, while the poorest visibility is east of the Mississippi River and in the urban areas of California. Aerosol concentrations' spatial trends generally follow this East-West trend, and fine mass concentrations are about a factor of four greater in the East than West, with sulfates and organics being the largest constituents. Sulfates are the largest single contributor to visibility degradation, with nitrates and organics contributing significantly in some regions of the country. In both the East and the West, historical changes in visibility show a high degree of correlation with increases in sulfur dioxide emissions. Source receptor modeling shows that in the Southwest, southern California, copper smelters in southern Arizona, and large sulfur dioxide sources along the Gulf Coast of Mexico contribute to elevated sulfate levels. A coal fired power plant and wood processing facilities contribute to elevated sulfate in the Northwest, while a nickel smelter in Canada and coal fired power plants in the New York and Philadelphia area are the cause of high sulfate concentrations in the Northeast. Coal fired power plants along the Ohio River Valley are one of the single largest contributors to elevated sulfate in both Shenandoah and Great Smoky Mountains National Parks.

Cancer risk among workers at a copper/nickel smelter and nickel refinery in Finland

A total of 1,388 workers employed for at least 3 months at a copper/nickel smelter and nickel refinery were followed up for cancer from 1953 to 1987 through the Finnish Cancer Registry. There were 1,339 male and 49 female workers, making a total of 27,130 and 706 person-years, respectively. All of the women worked in the refinery, which opened in 1960, the same year the smelting of nickel began. A total of 67 cancers were diagnosed among the men, the standardized incidence ratio for all cancers being 1.0. No cancer was found among the women (1.8 expected). The risk of cancer among men was analysed according to primary site, exposure to nickel, type of work, years since first exposure and age at diagnosis. In the subcohort of nickel refinery workers, one case of sinonasal cancer was observed, against 0.02 expected, but otherwise no significantly increased risks of cancer were found. In addition to the small size of the cohort, the non-positive finding concerning lung cancer might be related to the relatively low arsenic exposure and, perhaps, to the late commencement of nickel production.

Physical Modelling of Thermal Stratification, Bottom Build-Up and Mixing in Submerged ARC Electric Smelting

AbstractA one-tenth scale model of a portion of a submerged arc electric furnance for nickel smelting is constructed. By using a 52 wt% aqueous calcium solution to simulate the matte, solid calcium chloride hydrates are precipitated on the bottom of the furnace in an analogous manner to metallic precipitation from a matte phase. Mineral oil is used to simulate the slag. Reasonable similarity compared to the full scale furnace is achieved in the Prandtl, Grashof and Froude groups for both the calcium chloride solution and the oil phase. Furthermore, electric resistance heating from the top electrodes and cooling from a bottom water jacket are arranged to simulate conductive heat transfer in the full-scale furnace. It is found that with the imposed heat flux, the oil and calcium chloride solutions behave as if they are stagnant. Gas injection significantly reduces the thickness of the precipitate layer, and reduces the stratification in the oil and calcium chloride. Thermal mixing times are found to be cons...

Physical Modelling of Thermal Stratification, Bottom Build-Up and Mixing in Submerged ARC Electric Smelting

A one-tenth scale model of a portion of a submerged arc electric furnance for nickel smelting is constructed. By using a 52 wt% aqueous calcium solution to simulate the matte, solid calcium chloride hydrates are precipitated on the bottom of the furnace in an analogous manner to metallic precipitation from a matte phase. Mineral oil is used to simulate the slag. Reasonable similarity compared to the full scale furnace is achieved in the Prandtl, Grashof and Froude groups for both the calcium chloride solution and the oil phase. Furthermore, electric resistance heating from the top electrodes and cooling from a bottom water jacket are arranged to simulate conductive heat transfer in the full-scale furnace. It is found that with the imposed heat flux, the oil and calcium chloride solutions behave as if they are stagnant. Gas injection significantly reduces the thickness of the precipitate layer, and reduces the stratification in the oil and calcium chloride. Thermal mixing times are found to be considerably longer with electrical heating because the thermal stratification opposes mixing. Consequently, previous work on mixing in isothermal water models cannot be applied to top-heated vessels, such as electric and reverbatory furnaces.

Dynamic process plant simulation and scheduling: an expert systems approach

The secure operation of a complex industrial process, such as a Steelmaking Meltshop or Nickel Smelter, depends almost entirely on a harmonic working relationship between the human operator and the real time process control environment. The introduction of sophisticated real time monitoring systems and faster than real time decision making modules, requires a new approach to dynamic process plant simulation, scheduling and production optimization under varying operating constraints. Based on the proven Expert Systems Methodologies of Knowledge Engineering and Rule-Based Logistics, The ADSI Scheduling Advisor has been successfully implemented on the shop floor of serveral major base metals producing facilities.

A Review of Nickel Pyrometallurgical Operations

While the vast majority of the world’s nickel is produced using pyrometallurgical techniques, the equipment and processes employed in such production encompass a variety of technologies. Even though certain patterns are followed by many companies, the nature of the raw materials dictates how process parameters will vary from smelter to smelter. In addition, much remains unknown about nickel smelting. Further work is clearly required in such areas as the thermochemistry of sulfide, oxide and metal systems, correlation of industrial data with theoretical information and techniques to improve equipment design.

Copper, nickel, and iron levels in pelage of red squirrels living near the ore smelters at Sudbury, Ontario, Canada

Geographical and seasonal variabilities in pelage metal levels of the red squirrel (Tamiasciurus hudsonicus) were studied in wild populations subject to different degrees of contaminant fallout from the copper–nickel smelters at Sudbury, Ontario. Levels of copper and iron in recently emerged pelage (10–12 and 13–20 μg∙g−1, respectively) did not differ among animals from highly contaminated, moderately contaminated, and noncontaminated sites, thus indicating minimal metal loading via endogenous routes. Nickel levels were significantly elevated for animals at the two contaminated sites relative to the control group; however, such increases are believed to reflect external contamination from environmental sources and (or) cross-contamination between old and new pelage coats. Pelage in the premoult condition, having been subjected to exogenous influences during the pelage year, showed higher levels of all three metals at one or both of the contaminated sites but not at the control site. Relative increases of nickel, copper, and iron coincided with atmospheric loading ratios reported for the Sudbury smelters, thus confirming the latter as the source. Nickel gains conformed to a previously reported model in that pelage burdens varied as a simultaneous function of duration of exposure to the environment and reciprocal of distance from the pollution source. Element-specific variabilities are discussed in relation to the use of pelage and choice of elements in monitoring smelter emission fallout.

Carcinogenicity of occupational nickel exposures: an evaluation of the epidemiological evidence.

The health effects documented in recent epidemiological studies of nickel-exposed workers relate to past exposures, mostly of unknown magnitude and unknown nickel speciation. Major studies have been carried out at nickel smelters and refineries. Although each study suffers from some deficiencies, as is common in such retrospective studies, the findings in concert strongly indicate that nickel emitted from the calcining and sintering operations is a potent carcinogen resulting in nasal and pulmonary cancers. Some risk appears to be present in other refinery operations, such as Orford furnace, copper and nickel sulfate, and crushing departments, and one study has suggested a risk associated with soluble nickel compounds in the electrolysis department, although this finding has not been confirmed. Only one study demonstrated an exposure-response relationship, which, however, was not statistically significant. Other studies showed a relationship between increased exposure time and augmented cancer risk. In nickel-using industries, no excess cancer related to nickel exposures has been demonstrated beyond doubt; concurrent exposures to other potential carcinogens constitute a confounding variable that makes interpretation difficult. However, the studies have not excluded that a cancer hazard may be present outside the nickel-producing facilities. Further, case-referent studies of respiratory cancers suggest that a nickel-related etiology may well exist in the nickel-using industries. As the exact identity of the carcinogenic form or forms of nickel remains unknown, exposure to all nickel compounds should be kept as low as reasonably achievable.

Development and mine operation at Rio Tuba nickel mine

Rio Tuba Nickel Mining Corporation is one of the three companies in the Philippines mining Ni oxide ores; the other two are Nonoc Mining and Industrial Corporation and Hinatuan Mining Company. It has been exporting garnieritic Ni ore to the Japanese smelters since 1977 from its mine located at Rio Tuba, Palawan. It ranks third among the major suppliers of Ni oxide ores to Japan. Rio Tuba ore has high moisture, lower Ni content compared to ores supplied to Japanese smelters from other sources, and notable occurrence of boulders and hard saprolite of ore grade. To minimize the increasing cost of fuel oil consumed in the reduction of ore moisture when using a rotary kiln, the company adopted solar drying and suspended the use of the rotary dryer. If not of this significant inovation in saving oil energy cost, the company would have suspended operation. To attain the chemical composition and maximum size required of Rio Tuba ore by the nickel smelters, a rigid ore control procedure from the bench's faces up to the loading of ore vessels is necessary. This paper summarizes also the geology of the deposits, exploration, development, stripping, mining and sizing, aside from solar drying and grade control.

播磨事業所における初期ISP製錬法の技術の確立とその後の発展について

Harima Works was commissioned in 1966 firstly introducing the Imperial Smelting Process (simulataneouszinc and lead smelting process) in Japan.Most part of the plant, however, was designed by Sumitomo taking accumulated technologies of its long and extensive experience in copper and nickel smelting operations.It was built as a smelter complex consisting of not only a sinter and ISF plant but also a zinc & leadrefinery.The SO2 gas is sent to the acid plant of a neighbouring chemical company.The ISF has a shaft area of 15.3m2 which is smaller than the standard one of 17.2m2 and the initial capacity was designed to produce 3000T/M of zinc and 1500T/M of bullion.The operation has been smooth and stable since the start-up.The production capacity has been stepped up to 6600T/M of zinc and 2500TIM of bullion with accumulation of various modifications and improvements through twenty years' operation.As a result, Harima Works has established its position as one of the most successful among the thirteen ISP factories in eleven countries in the world.

The effect of nickel and copper deposition from a mining and smelting complex on coniferous regeneration in the boreal forest of northern Manitoba

Airborne pollutants in the form of SO2 and heavy metals have been dispersed over the boreal forest in the Thompson area of northern Manitoba since 1961. Metal deposition has been found in soils and plant material to a distance of 35 km from the Inco nickel smelter. Studies were initiated in 1979 to determine effects of Ni and Cu on coniferous regeneration of jack pine (Pinus banksiana Lamb.) and black spruce (Picea mariana (Mill) BSP.).Studies included metal accumulation in cones, effects on seed quality, seed germination and seedling response in metal contaminated soils. Nickel and Cu accumulation in cones of both species declined rapidly with distance from the smelter. Seed quality and germination potential was not related to metals in cones or air pollutant influence in general. Nickel and Cu accumulation in surface organic soils was inversely related to distance from the smelter. A significant inverse correlation was determined between seedling growth and Cu/Ni concentrations in surface organic soils. Metal accumulation in soils within 5 km of the nickel smelter inhibited root growth of conifer seedlings.

A study of mortality in workers engaged in the mining, smelting, and refining of nickel. I: Methodology and mortality by major cause groups.

Following the publication of the NIOSH nickel criteria document in 1977, the Joint Occupational Health Committee of the International Nickel Company (INCO) commissioned a mortality study of the company's Ontario workforce. This paper describes the detailed methodology and primary mortality results of the ensuing study; subsequent papers will describe more detailed findings of cause-specific mortality. An historical prospective mortality study of approximately 54,000 INCO workers has been conducted. Men with six months or more of service were followed for mortality during a 35-year period by computerized record linkage to the Canadian National Mortality Data Base. From a company-provided list of men known to have died and through independent follow-up of a random sample of 1,000 subjects of unknown status, we estimate a mortality ascertainment rate of 95%. Cause-specific standardized mortality ratios calculated with respect to Ontario provincial mortality rates indicate an excess of accidental deaths in men working in the Sudbury area and an excess of cancer deaths at the company's Port Colborne nickel refinery. A strong healthy worker effect was found for both all-disease mortality ad cancer mortality. The lower than expected mortality persisted for about 15 years beyond initial hiring.

A Study of Mortality in Workers Engaged in the Mining, Smelting, and Refining of Nickel: Ii: Mortality from Cancer of the Respiratory Tract and Kidney

This paper describes observed and expected mortality from cancers of the lung, larynx, nose, and kidney in a cohort of 54,509 nickel workers followed for 35 years. For analysis purposes the cohort was subdivided into men with and without service in one of the three high nickel dust areas of the operation: the Sinter Plants at Copper Cliff and Coniston, and the Leaching, Calcining and Sintering (LC&S) department at Port Colborne. At Copper Cliff Sinter Plant workers experienced three times the expected number of lung cancer deaths; the SMR rose steeply with increasing duration of service peaking at 943 with 10 to 15 years. A similar overall excess risk of lung cancer was seen in the smaller Coniston Sinter Plant again with an indication of an exposure risk gradient. Men in the LC&S department at Port Colborne also experienced a dose related excess risk of lung cancer death that rose to an SMR of 806 with 20 to 25 years of service. Nasal cancer deaths were increased at both the Copper Cliff Sinter Plant (6 deaths) and the LC&S department at Port Colborne (19 deaths), representing SMRs of 3,704 and 7,755, respectively, for this rare cancer. Laryngeal cancer and kidney cancer, both previously associated with nickel, were not in excess in these high risk groups. A further exploration of death from these causes in the lower exposure remainder of the cohort revealed an epidemiologically modest elevation in lung cancer death in miners (probably not nickel related) and parts of the Copper Refinery. No evidence of laryngeal cancer excess was found.(ABSTRACT TRUNCATED AT 250 WORDS)

Deironization of Ni&amp;ndash;Cu Concentrated Matte with SiO&lt;SUB&gt;2&lt;/SUB&gt;&amp;ndash;Na&lt;SUB&gt;2&lt;/SUB&gt;SO&lt;SUB&gt;4&lt;/SUB&gt; Flux

A mathematical description of the variation of normalized concentrations of components in matte during converting has been proposed for a 50 ton converter of a Chinese nickel smelter. Two process parameters, molar ratio of desulfurization to deironization of matte converting, dnS⁄dnFe, and sulfur deficiency fraction of matte, δS, which characterize the matte converting process, have been deduced as a function of iron content in matte. Laboratory experiments and plant tests of further deironization of concentrated matte were carried out to obtain a final matte product with an iron content less than 1% and a sulfur content more than 20% by mass.