Use of Aspergillus niger in the bioleaching of colemanite for the production of boric acid

Colemanite is one of the most important underground riches of Turkey, having approximately 60% of the world boron deposits, and it has a large portion in the deposits. In this study, chemical leaching and biological leaching methods were used for production of boric acid from colemanite (2CaO Â· 3B3...

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Autores principales:	Bayat,Oktay, Arslan,Volkan, Bayat,Belgin
Lenguaje:	English
Publicado:	Pontificia Universidad Católica de Valparaíso 2011
Materias:	Aspergillus niger bioleaching boric acid chemical leaching colemanite oxalic acid
Acceso en línea:	http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582011000300007
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spelling	oai:scielo:S0717-345820110003000072011-09-23Use of Aspergillus niger in the bioleaching of colemanite for the production of boric acidBayat,OktayArslan,VolkanBayat,Belgin Aspergillus niger bioleaching boric acid chemical leaching colemanite oxalic acid Colemanite is one of the most important underground riches of Turkey, having approximately 60% of the world boron deposits, and it has a large portion in the deposits. In this study, chemical leaching and biological leaching methods were used for production of boric acid from colemanite (2CaO Â· 3B3O3 Â· 5H2O) (Emet-KÃ¼tahya, Turkey). Oxalic acid concentration, temperature, stirring time and solid-to-liquid ratio were taken as parameters in the chemical leaching process. It was found that the dissolution rate increases with increasing oxalic acid concentration and temperature but it decreases at higher solid-to-liquid ratios in the chemical leaching process. Using optimum conditions (d100 = 0.075 mm; 5% solids by weight; 0.55 M oxalic acid; 80 Â± 2ÂºC leaching temperature; 150 rpm stirring speed; 90 min leaching time) for colemanite sample (28.05% B2O3) on chemical leaching with oxalic acid experiments, the calculated boric acid extraction efficiency from colemanite ore was 97.89%. Optimum conditions on bioleaching of Emet-KÃ¼tahya, Turkey colemanite ores using the fungus Aspergillus niger were found to be as follows: reaction temperature 25 Â± 2ºC; solid-to-liquid ratio 5% solids by weight; d100 = 0.075 mm; stirring speed 150 rpm; initial the fungus populations in the inocula about 3 x 10(7) cells/ml and reaction time 21 days. The calculated boric acid extraction efficiency from colemanite ore was 90.18% under the optimum conditions. Bioleachate contained 12.95 g/l B2O3, 6.60 g/l Ca and 0.087 g/l Mg. Compared with chemical leaching at 5% pulp density, the fungus was less efficient in the extraction of B2O3 from colemanite but the difference in the extraction yields between the two processes was less than 10%. Although bioleaching generally requires a longer period of operation compared to chemical leaching, these results suggest that bioleaching by A. niger may be an alternative or adjunct to conventional physicochemical treatment processes of colemanite to produce boric acid.info:eu-repo/semantics/openAccessPontificia Universidad Católica de ValparaísoElectronic Journal of Biotechnology v.14 n.3 20112011-05-01text/htmlhttp://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582011000300007en
institution	Scielo Chile
collection	Scielo Chile
language	English
topic	Aspergillus niger bioleaching boric acid chemical leaching colemanite oxalic acid
spellingShingle	Aspergillus niger bioleaching boric acid chemical leaching colemanite oxalic acid Bayat,Oktay Arslan,Volkan Bayat,Belgin Use of Aspergillus niger in the bioleaching of colemanite for the production of boric acid
description	Colemanite is one of the most important underground riches of Turkey, having approximately 60% of the world boron deposits, and it has a large portion in the deposits. In this study, chemical leaching and biological leaching methods were used for production of boric acid from colemanite (2CaO Â· 3B3O3 Â· 5H2O) (Emet-KÃ¼tahya, Turkey). Oxalic acid concentration, temperature, stirring time and solid-to-liquid ratio were taken as parameters in the chemical leaching process. It was found that the dissolution rate increases with increasing oxalic acid concentration and temperature but it decreases at higher solid-to-liquid ratios in the chemical leaching process. Using optimum conditions (d100 = 0.075 mm; 5% solids by weight; 0.55 M oxalic acid; 80 Â± 2ÂºC leaching temperature; 150 rpm stirring speed; 90 min leaching time) for colemanite sample (28.05% B2O3) on chemical leaching with oxalic acid experiments, the calculated boric acid extraction efficiency from colemanite ore was 97.89%. Optimum conditions on bioleaching of Emet-KÃ¼tahya, Turkey colemanite ores using the fungus Aspergillus niger were found to be as follows: reaction temperature 25 Â± 2ºC; solid-to-liquid ratio 5% solids by weight; d100 = 0.075 mm; stirring speed 150 rpm; initial the fungus populations in the inocula about 3 x 10(7) cells/ml and reaction time 21 days. The calculated boric acid extraction efficiency from colemanite ore was 90.18% under the optimum conditions. Bioleachate contained 12.95 g/l B2O3, 6.60 g/l Ca and 0.087 g/l Mg. Compared with chemical leaching at 5% pulp density, the fungus was less efficient in the extraction of B2O3 from colemanite but the difference in the extraction yields between the two processes was less than 10%. Although bioleaching generally requires a longer period of operation compared to chemical leaching, these results suggest that bioleaching by A. niger may be an alternative or adjunct to conventional physicochemical treatment processes of colemanite to produce boric acid.
author	Bayat,Oktay Arslan,Volkan Bayat,Belgin
author_facet	Bayat,Oktay Arslan,Volkan Bayat,Belgin
author_sort	Bayat,Oktay
title	Use of Aspergillus niger in the bioleaching of colemanite for the production of boric acid
title_short	Use of Aspergillus niger in the bioleaching of colemanite for the production of boric acid
title_full	Use of Aspergillus niger in the bioleaching of colemanite for the production of boric acid
title_fullStr	Use of Aspergillus niger in the bioleaching of colemanite for the production of boric acid
title_full_unstemmed	Use of Aspergillus niger in the bioleaching of colemanite for the production of boric acid
title_sort	use of aspergillus niger in the bioleaching of colemanite for the production of boric acid
publisher	Pontificia Universidad Católica de Valparaíso
publishDate	2011
url	http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582011000300007
work_keys_str_mv	AT bayatoktay useofaspergillusnigerinthebioleachingofcolemanitefortheproductionofboricacid AT arslanvolkan useofaspergillusnigerinthebioleachingofcolemanitefortheproductionofboricacid AT bayatbelgin useofaspergillusnigerinthebioleachingofcolemanitefortheproductionofboricacid
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Use of Aspergillus niger in the bioleaching of colemanite for the production of boric acid

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