2
complexes and can potentially improve solubilization
rate and extent by thermodynamically favoring the reac-
tion towards increased solubility. Second, the bio-solvent
can be produced via fermentation and potentially recov-
ered through less environmentally costly methods than
conventional mineral acids. We are developing a range of
bio-solvents that can be tuned based on material (e.g., ores,
concentrates, tailings) and selective removal needs (e.g.,
gangue or penalty elements) to act as targeted extractants.
We are focusing on tuning bio-solvents that can effectively
remove silica, aluminum, magnesium, and calcium present
in silicates, such as kaolinite and other secondary alumino-
silicates. Gangue removal has the potential to improve
metal recovery (e.g., through improved separation via flota-
tion), upgrade ores and concentrates, and remove compo-
nents that negatively impact downstream processing, such
as smelting.
The natural generation of calcite minerals is a ubiqui-
tous process found in a wide range of environments (Naveed
et al. 2020). One such process is known as microbially-
induced carbonate precipitation (MICP). Bio-cementation
is rapidly expanding in the field of environmental engineer-
ing and relevant applications of this technology include soil
stabilization, erosion control, dust suppression, ground-
water remediation, construction material fabrication and
restoration, toxic metal immobilization, and CO2 seques-
tration (Mujah et al. 2017, Proudfoot et al. 2022, Song et
al. 2022). We are developing both enzymatic and microbial
approaches for agglomerating and controlling the strength
and geotechnical stability of a range of materials, including
ore stockpiles and tailings.
EXPERIMENTAL
Microbiome Database/Biobank
While the geochemical profile at mining sites is usually
extensively characterized, the microbiome is largely unex-
plored even from a basic diversity standpoint, let alone in
terms of understanding the genetic functional potential of
microbes. Allonnia has obtained samples from mine sites
in Australia, Africa, and North America to characterize
the microbiome in these mineral-rich environments. We
extracted DNA for amplicon sequencing and taxonomic
analysis not only for bacteria and archaea but also for fungi.
In addition, we have isolated hundreds of organisms on
various media types to facilitate whole genome sequencing
and build Allonnia’s bio-bank. Living in extreme environ-
ments, microbes evolve incredible genetic mechanisms to
utilize and/or cope with high levels of elements such as
copper, cobalt, iron, aluminum, etc. that would be toxic
to most forms of life. Cataloging this microbial diversity,
deciphering the genetic potential, and building a biobank
of isolated organisms gives us a starting point for harnessing
these microbes and furthering their capabilities to trans-
form and sequester target compounds or perform targeted
processes across a range of applications.
Bio-Solubilization
Allonnia is evaluating a range of bio-solvents for their abil-
ity to selectively solubilize gangue minerals, and remove
aluminum (Al), silica (SiO2), calcium (Ca), and magne-
sium (Mg) from the solids. The bio-solvents are composed
of microbial metabolites present within individual bacteria,
fungi, and/or microbial consortia that have shown poten-
tial for selective solubilization in natural and laboratory
conditions.
We have extended solubilization experiments across
a range of ore types, tailings, and individual minerals to
understand baseline bio-solvent performance and key
operational parameters. The results presented in this paper
include an ore material that has been pulverized to a P95 of
106 microns and silica-rich tailings with a similar size dis-
tribution. Operational parameter evaluations have included
solid loading (5 to 30% solids by weight) and a range of
temperatures (30 to 80°C) under well-stirred conditions.
The data presented in this paper were analyzed by a
commercial analytical laboratory using lithium borate
fusion disks measured on a wavelength dispersive X-ray flu-
orescence spectrometer (WD-XRF) and semi-quantitative
estimates of mineralogy were determined by X-ray diffrac-
tion (XRD) using the Rietveld refinement method. Both
methods included industry-standard QA/QC reporting
requirements.
Bio-Cementation
Allonnia is evaluating promising microbes from our bio-
bank for MICP ability with a goal of also limiting urea
and Ca additions to create more economic, sustainable,
and environmentally friendly bio-cement formulations. In
addition, we are exploring applications for enzyme-induced
calcite precipitation (EICP) and the production of micro-
bial enzymes at scale for mining applications. As part of
our experimental work, we have been testing baseline reac-
tion conditions and developing cementation formulas and
deployment strategies. We are exploring key factors such
as curing time, moisture content, enzyme activity, tem-
perature, and pressure on unconfined compressive strength
achieved through the bio-cementation of mining materials.
Further, we are testing the ability of the ore and tailings
bio-cement to withstand variable environmental condi-
tions (e.g., heat and moisture) and exploring how different
complexes and can potentially improve solubilization
rate and extent by thermodynamically favoring the reac-
tion towards increased solubility. Second, the bio-solvent
can be produced via fermentation and potentially recov-
ered through less environmentally costly methods than
conventional mineral acids. We are developing a range of
bio-solvents that can be tuned based on material (e.g., ores,
concentrates, tailings) and selective removal needs (e.g.,
gangue or penalty elements) to act as targeted extractants.
We are focusing on tuning bio-solvents that can effectively
remove silica, aluminum, magnesium, and calcium present
in silicates, such as kaolinite and other secondary alumino-
silicates. Gangue removal has the potential to improve
metal recovery (e.g., through improved separation via flota-
tion), upgrade ores and concentrates, and remove compo-
nents that negatively impact downstream processing, such
as smelting.
The natural generation of calcite minerals is a ubiqui-
tous process found in a wide range of environments (Naveed
et al. 2020). One such process is known as microbially-
induced carbonate precipitation (MICP). Bio-cementation
is rapidly expanding in the field of environmental engineer-
ing and relevant applications of this technology include soil
stabilization, erosion control, dust suppression, ground-
water remediation, construction material fabrication and
restoration, toxic metal immobilization, and CO2 seques-
tration (Mujah et al. 2017, Proudfoot et al. 2022, Song et
al. 2022). We are developing both enzymatic and microbial
approaches for agglomerating and controlling the strength
and geotechnical stability of a range of materials, including
ore stockpiles and tailings.
EXPERIMENTAL
Microbiome Database/Biobank
While the geochemical profile at mining sites is usually
extensively characterized, the microbiome is largely unex-
plored even from a basic diversity standpoint, let alone in
terms of understanding the genetic functional potential of
microbes. Allonnia has obtained samples from mine sites
in Australia, Africa, and North America to characterize
the microbiome in these mineral-rich environments. We
extracted DNA for amplicon sequencing and taxonomic
analysis not only for bacteria and archaea but also for fungi.
In addition, we have isolated hundreds of organisms on
various media types to facilitate whole genome sequencing
and build Allonnia’s bio-bank. Living in extreme environ-
ments, microbes evolve incredible genetic mechanisms to
utilize and/or cope with high levels of elements such as
copper, cobalt, iron, aluminum, etc. that would be toxic
to most forms of life. Cataloging this microbial diversity,
deciphering the genetic potential, and building a biobank
of isolated organisms gives us a starting point for harnessing
these microbes and furthering their capabilities to trans-
form and sequester target compounds or perform targeted
processes across a range of applications.
Bio-Solubilization
Allonnia is evaluating a range of bio-solvents for their abil-
ity to selectively solubilize gangue minerals, and remove
aluminum (Al), silica (SiO2), calcium (Ca), and magne-
sium (Mg) from the solids. The bio-solvents are composed
of microbial metabolites present within individual bacteria,
fungi, and/or microbial consortia that have shown poten-
tial for selective solubilization in natural and laboratory
conditions.
We have extended solubilization experiments across
a range of ore types, tailings, and individual minerals to
understand baseline bio-solvent performance and key
operational parameters. The results presented in this paper
include an ore material that has been pulverized to a P95 of
106 microns and silica-rich tailings with a similar size dis-
tribution. Operational parameter evaluations have included
solid loading (5 to 30% solids by weight) and a range of
temperatures (30 to 80°C) under well-stirred conditions.
The data presented in this paper were analyzed by a
commercial analytical laboratory using lithium borate
fusion disks measured on a wavelength dispersive X-ray flu-
orescence spectrometer (WD-XRF) and semi-quantitative
estimates of mineralogy were determined by X-ray diffrac-
tion (XRD) using the Rietveld refinement method. Both
methods included industry-standard QA/QC reporting
requirements.
Bio-Cementation
Allonnia is evaluating promising microbes from our bio-
bank for MICP ability with a goal of also limiting urea
and Ca additions to create more economic, sustainable,
and environmentally friendly bio-cement formulations. In
addition, we are exploring applications for enzyme-induced
calcite precipitation (EICP) and the production of micro-
bial enzymes at scale for mining applications. As part of
our experimental work, we have been testing baseline reac-
tion conditions and developing cementation formulas and
deployment strategies. We are exploring key factors such
as curing time, moisture content, enzyme activity, tem-
perature, and pressure on unconfined compressive strength
achieved through the bio-cementation of mining materials.
Further, we are testing the ability of the ore and tailings
bio-cement to withstand variable environmental condi-
tions (e.g., heat and moisture) and exploring how different