Capsules of viable biomining microorganisms, with alginate and iron ions called biosigma bioleaching seeds (BBS) and their use for inoculation of these microorganisms in bioleaching processes
Inventors
Martinez Bellange, Patricio Ernesto • Parada Valdecantos, Pilar Angelica
Assignees
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Publication Number
US-10131961-B2
Publication Date
2018-11-20
Expiration Date
Abstract
The invention refers to viable biomining microorganisms encapsulated in alginate capsules, called BioSigma Bioleaching Seeds or BBS, wherein the alginate capsules have iron (II) and/or iron (III) ions as the cross-linking cations, and the usage of these capsules in the inoculation of these microorganisms in bioleaching processes.
Core Innovation
The invention is directed to BioSigma Bioleaching Seeds (BBS), comprising viable biomining microorganisms encapsulated in alginate capsules cross-linked with Fe(II) and/or Fe(III) ions. The BBS present a consortium of microorganisms inside the capsules embedded in a matrix of alginate and iron ions used as cross-linking cations, with capsule pH 1–2.
The problem addressed is the need to increase bioleaching rate in a heap or dump under toxic conditions for microorganisms. The toxic conditions are associated with an irrigation solution comprising water and raffinate, where the raffinate is formed by Cu, Fe(III), Fe(II), SO4-2, Cl− and heavy metals.
The BBS are used as an inoculum for bioleaching by inoculating an ore in a bioleaching heap or dump with a proportion of BBS capsules to form a homogeneous mixture of inoculum and ore, followed by stockpiling the heap or dump and then irrigating with the water/raffinate irrigation solution. The encapsulated consortium is constituted and present inside the capsules at specified concentration levels.
Claims Coverage
The independent claim covers a method of increasing bioleaching rate in a heap or dump under toxic conditions by inoculating ore with iron-cross-linked alginate capsules (BBS) containing a defined consortium of viable microorganisms, forming a homogeneous inoculum/ore mixture, stockpiling, and irrigating with water and raffinate.
BioSigma Bioleaching Seeds capsules with alginate and iron cross-linking for a microorganism consortium
Providing BioSigma Bioleaching Seeds (BBS) capsules that comprise a consortium of viable microorganisms in a matrix of alginate and iron ions, whether Fe(II) or Fe(III) or a mixture thereof and used as cross-linking cations, with the BBS capsules comprising a mixture of a solution of sodium alginate and a suspension of microorganisms, and being the BBS capsules in a spherification solution that comprises Fe(II) or Fe(III) ions, or a mixture thereof; the consortium being present inside the BBS capsules at concentrations above 10^3 microorganisms/mL of the solution of sodium alginate.
Defined multi-species consortium inside BBS capsules
Wherein the consortium of microorganisms is constituted by at least 1.00×10^3 microorganisms/mL of Acidithiobacillus ferrooxidans Wenelen DSM 16786, at least 9.74×10^6 microorganisms/mL of Acidithiobacillus thiooxidans, at least 1.00×10^3 microorganisms/mL of Acidiphilium spp., at least 1.00×10^3 microorganisms/mL of Leptospirillum spp., and at least 3.42×10^6 microorganisms/mL of Ferroplasma spp.
Homogeneous inoculation of ore with BBS capsules proportion and stockpiling
Inoculating an ore in a bioleaching heap or dump with a proportion of BBS capsules between 0.01% and 99% by dry weight per gram of ore to form a homogeneous mixture of inoculum and ore, and then stockpiling the heap or dump after the inoculation is performed.
Irrigation using water and raffinate formed by specified ionic and heavy metal components
Irrigating the stockpiled heap or dump with an irrigation solution comprising water and raffinate, wherein the raffinate is formed by Cu, Fe(III), Fe(II), SO4-2, Cl− and heavy metals.
The independent claim centers on using BBS capsules containing a defined consortium of viable microorganisms embedded in an alginate matrix cross-linked with Fe(II)/Fe(III), then inoculating ore to form a homogeneous mixture, stockpiling, and irrigating with water and raffinate under toxic conditions defined by Cu, Fe(III), Fe(II), SO4-2, Cl− and heavy metals.
Stated Advantages
Protection against extreme acidity and toxins for the inoculated microorganisms.
Improved handling and storage of the inoculum.
Homogeneous inoculation of ore when the BBS are mixed as solid particles.
Improved bioleaching column performance versus conventional liquid inoculation.
Earlier bioleaching start (about 20 days) under raffinate/toxic conditions.
Documented Applications
Bioleaching heaps or dumps where an ore is inoculated with BBS capsules and irrigated with a water/raffinate irrigation solution under toxic conditions.
Bioleaching inoculation under raffinate conditions containing Cu, Fe(III), Fe(II), SO4-2, Cl− and heavy metals.
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