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Exposure of workers to nickel, copper and lead in a base metal recovery plant and laboratory / Chrisna StapelbergStapelberg, Chrisna January 2011 (has links)
Objectives: The objectives of this study were to establish the extent of dermal and respiratory
exposure at selected locations at a South African platinum mine. The study included exposure to lead
oxide fumes in an assay laboratory, nickel sulfate powder at a nickel sulfate crystallizer circuit and
packing site and metallic copper dust whilst executing copper stripping.
Methods: In an availability study, the dermal metal exposures were measured before, during and at
the end of shifts. Dermal exposure samples were taken with GhostwipesTM from the dominant hand,
wrist and forehead. Wipes were analyzed using Inductively Coupled Plasma-Atomic Emission
Spectroscopy (ICP-AES). Wipe samples were taken from surfaces in the workplace and analyzed
according to NIOSH 9102, using ICP-AES. Personal and static inhalable dust samples were taken
and the dust samples were analyzed according to NIOSH 7300, using ICP-AES. A validated
questionnaire was used to evaluate self reported dermatological complaints of the workers at the fire
assay laboratory and base metal recovery plant.
Results: 100% of the nickel respiratory exposures and 36.8% of the lead respiratory exposures were
above the occupational exposure limits (OEL). Copper respiratory exposure was present but less
significant with a geometric mean of 0.071 mg m-3. All of the dermal lead measurements and the
majority of the nickel and copper dermal measurements were below the limit of detection. Nickel
surface contamination was the most significant and ranged between 8.430 μg cm-2 and
387.488 μg cm-2. Only 30% of the copper surface sample results were below the detection limit with
a maximum surface sample of 14.41 μg cm-2. Lead surface contamination was low with 90% of the
samples below the limit of detection. All of the workers at the nickel crystallizer circuit and packing
site had a Dalgard score above 1.3 and therefore are at a higher risk of developing a skin disease.
None of the workers at the copper stripping site had a significant Dalgard score and only one worker
at the fire assay laboratory had a score above 1.3 and therefore is at a higher risk of developing a skin
disease.
Conclusions: Recommendations were made to lower the exposure to inhalable lead and nickel. The
low lead dermal measurements may be due to adequate personal protective equipment usage and
hygiene practices. Although the ethnicity of the workers may be the reason for the low incidence of
dermatological complaints, the Dalgard score indicated that five workers are at risk of developing skin
diseases. / Thesis (M.Sc. (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2011
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Exposure of workers to nickel, copper and lead in a base metal recovery plant and laboratory / Chrisna StapelbergStapelberg, Chrisna January 2011 (has links)
Objectives: The objectives of this study were to establish the extent of dermal and respiratory
exposure at selected locations at a South African platinum mine. The study included exposure to lead
oxide fumes in an assay laboratory, nickel sulfate powder at a nickel sulfate crystallizer circuit and
packing site and metallic copper dust whilst executing copper stripping.
Methods: In an availability study, the dermal metal exposures were measured before, during and at
the end of shifts. Dermal exposure samples were taken with GhostwipesTM from the dominant hand,
wrist and forehead. Wipes were analyzed using Inductively Coupled Plasma-Atomic Emission
Spectroscopy (ICP-AES). Wipe samples were taken from surfaces in the workplace and analyzed
according to NIOSH 9102, using ICP-AES. Personal and static inhalable dust samples were taken
and the dust samples were analyzed according to NIOSH 7300, using ICP-AES. A validated
questionnaire was used to evaluate self reported dermatological complaints of the workers at the fire
assay laboratory and base metal recovery plant.
Results: 100% of the nickel respiratory exposures and 36.8% of the lead respiratory exposures were
above the occupational exposure limits (OEL). Copper respiratory exposure was present but less
significant with a geometric mean of 0.071 mg m-3. All of the dermal lead measurements and the
majority of the nickel and copper dermal measurements were below the limit of detection. Nickel
surface contamination was the most significant and ranged between 8.430 μg cm-2 and
387.488 μg cm-2. Only 30% of the copper surface sample results were below the detection limit with
a maximum surface sample of 14.41 μg cm-2. Lead surface contamination was low with 90% of the
samples below the limit of detection. All of the workers at the nickel crystallizer circuit and packing
site had a Dalgard score above 1.3 and therefore are at a higher risk of developing a skin disease.
None of the workers at the copper stripping site had a significant Dalgard score and only one worker
at the fire assay laboratory had a score above 1.3 and therefore is at a higher risk of developing a skin
disease.
Conclusions: Recommendations were made to lower the exposure to inhalable lead and nickel. The
low lead dermal measurements may be due to adequate personal protective equipment usage and
hygiene practices. Although the ethnicity of the workers may be the reason for the low incidence of
dermatological complaints, the Dalgard score indicated that five workers are at risk of developing skin
diseases. / Thesis (M.Sc. (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2011
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Avaliação de procedimentos alternativos para determinação de ouro e prata em amostras com alto teor de cobre empregando ICP - OESFreitas, Jorge Tadeu de 31 March 2010 (has links)
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Tese.pdf: 2432189 bytes, checksum: 2356da705977522f3d019892890a0c7f (MD5) / Paranapanema S.A / A determinação precisa de ouro e prata é particularmente requerida na
comercialização de materiais utilizados na Metalurgia do cobre, como concentrados de
minérios, sucatas e produtos metalúrgicos como: cobre revert, cobre blister, anodos de
cobre, etc. O método de Fusão e Copelação (Fire Assay) é considerado o mais confiável
para a separação e pré-concentração de Au e Ag e o mais aceito no comércio
internacional do cobre. Neste método, a amostra é fundida com um fluxo apropriado de
reagentes, de acordo com a sua composição química ou mineralógica, para decompor a
matriz e transformá-la em uma fase de silicatos, enquanto os metais nobres são
solubilizados em um metal formando uma liga, sendo chumbo o mais usado. A
temperatura de fusão geralmente está na faixa de 1000 a 1200 ºC. Esta tese buscou os
seguintes objetivos: desenvolver procedimento alternativo empregando digestão ácida e
quantificação por ICP OES para determinação de Au e Ag em amostras com alto teor de
cobre, que requer separação prévia do cobre tornando ainda mais laborioso o método de
Fire Assay (FA), além de propor melhorias para este método, como: o uso de nova
mistura de fundentes visando baixar a temperatura de fusão, uso de cobre para
solubilizar os metais nobres para foramação da liga em substituição ao chumbo e o
emprego de Forno Mufla por micro-ondas na etapa de copelação. Os resultados da
pesquisa mostraram que é possível introduzir melhorias mais simples e econômicas que
a obtida na automação da técnica de FA, como a redução da temperatura do forno pela
simples adição do reagente carbonato de potássio que possibilita a utilização de menores
temperaturas no processo de fusão e o uso de forno mufla de micro-ondas como
alternativa aos fornos elétricos convencionais. Com o desenvolvimento de método
alternativo para a determinação direta de Au e Ag em amostras de cobre metálico por
ICP OES, com o mesmo nível de exatidão e precisão que o método de FA, porém com
menor custo e tempo de análise, este trabalho abre perspectivas para pesquisa visando a
substituição do Pb, um elemento tóxico, pelo cobre, um metal reciclável, na
solubilização dos metais nobres e formação da liga no método de FA, para aplicação na
Metalurgia de cobre. / Precise determination of gold and silver is particularly required in the marketing
materials used in the metallurgy of copper, such as ore concentrates, scrap and
metallurgical products like: revert copper, copper blister, copper anodes, etc.. The
method of Fusion and Cupellation (Fire Assay) is considered the most reliable for the
separation and preconcentration of Au and Ag and more accepted in the international
trade of copper. In this method, the sample is fused with an appropriate flow of
reagents, according to their chemical composition and mineralogy, to decompose the
matrix and transform it into a phase of silicates, while the noble metals are dissolved in
a metal forming an alloy , and lead the most used. The melting temperature is usually in
the range 1000-1200 °C. This thesis has sought the following objectives: to develop an
alternative procedure using acid digestion and quantification by ICP OES for the
determination of Au and Ag in samples with high copper content, which requires
previous separation of the copper making it even more laborious method of Fire Assay
(FA) , and propose improvements to this method, such as the use of new blend of flux in
order to lower the melting temperature, use of copper to solubilize noble metals to form
alloy to replace lead and employment Muffle oven microwave in step cupellation. The
survey results showed that improvements can be made simpler and more economical
than the one obtained in the automation of the technique of FA, such as reducing the
oven temperature by the simple addition of the potassium carbonate that allows the use
of lower temperatures in the melting process muffle furnace and the use of microwave
as an alternative to conventional electric ovens. With the development of alternative
method for the direct determination of Au and Ag in samples of metallic copper by ICP
OES, with the same level of accuracy and precision that the method of FA, but with less
cost and time of analysis, this work opens perspectives for research aimed at the
substitution of Pb, a toxic element for copper, a metal recycled, the solubilization of
metals and alloy formation in the FA method, for application in the metallurgy of
copper.
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