The present invention generally relates to methods of biological reduction of metal-cyanide complexes after metal-cyanidation and methods of biologically hydrolysing cyanide. More particularly, the present invention allows the engineering of an integrated synthetic lixiviant biological system to be housed within a synthetic host (such as the cyanogenic Chromobacterium violaceum) for efficient precious metal recovery and toxic metal remediation of electronic waste; with up to four main components/modules in the design and engineering of the synthetic host: 1) synthetic cyanogenesis; 2) synthetic metal recovery; 3) synthetic cyanolysis; and 4) synthetic circuits for lixiviant biology. Bacteria capable of reducing ionic metal to ionic metal (such as gold or silver) as nanoparticles, comprising mercury(ll) reductase (MerA) comprising a substitution mutation at position V317, Y441, C464, A323D, A414E, G415I, E416C, L417I, I418D, or A422N, are also disclosed. Processes of synthetic cyanide lixiviant production using genetically engineered bacterium transformed with a heterologous hydrogen cyanide synthase gene and a heterologous 3-phosphoglycerate dehydrogenase mutant gene are also disclosed. Processes of synthetic cyanolysis using a genetically engineered bacterium transformed with a heterologous nitrilase gene are also disclosed.

THIS invention relates a method for processing a sulphide ore containing metal values comprising the integration of a sand heap leach (10) and a flotation process (12), providing a method which is suited to processing ores with significant quantities of leachable sulphides. The method includes a comminution step (14), and the classification of the comminuted ore into an oversize coarse fraction (16), a fine fraction (18) suitable for fine flotation and optionally an intermediate fraction (20) suitable for coarse flotation. A concentrate (30) containing iron sulphides from a fine flotation step (22) and optionally a concentrate (36) from a coarse flotation step (34) are blended with the oversize coarse fraction (16), to obtain a blended ore (39) is stacked and subjected to a heap leach process (40).

The present disclosure relates to the use of carbonaceous matter and a reagent comprising a thiocarbonyl functional group, for example, in a method for extracting a base metal such as copper from a material comprising the base metal. Such methods can comprise contacting the material under acidic conditions with the carbonaceous matter and the reagent comprising the thiocarbonyl functional group; and optionally recovering the base metal.

Present invention describes a biotechnological procedure to remove magnetic sulfur impurities from iron concentrate, wherein includes: to bioleach iron concentrate ores agglomerated in heaps under temperature condition between 5 and 35° C., inoculating the iron concentrate ores with Acidithiobacillus thiooxidans cultures, with an inoculum concentration 10.sup.4 and 10.sup.6 cel/g and addition of water supplemented with nitrogen and phosphorous source (0.01 to 0.5 g (NH.sub.4).sub.2HPO.sub.4/L), without potassium addition, adjusting pH between 1.0 and 9.0, and a feeding rate between 5 and 15 L/h/m.sup.2; this procedure allows a removal efficiency above 80% in 21 days, with a maximum iron loss of 3%.

Present invention describes a biotechnological procedure to remove magnetic sulfur impurities from iron concentrate, wherein includes: to bioleach iron concentrate ores agglomerated in heaps under temperature condition between 5 and 35° C., inoculating the iron concentrate ores with Acidithiobacillus thiooxidans cultures, with an inoculum concentration 10.sup.4 and 10.sup.6 cel/g and addition of water supplemented with nitrogen and phosphorous source (0.01 to 0.5 g (NH.sub.4).sub.2HPO.sub.4/L), without potassium addition, adjusting pH between 1.0 and 9.0, and a feeding rate between 5 and 15 L/h/m.sup.2; this procedure allows a removal efficiency above 80% in 21 days, with a maximum iron loss of 3%.

The invention provides an assay for identifying a bacterium capable of binding elemental heavy metal, comprising the following steps: cultivating a test bacterium in a suitable first culture medium; immersing at least a surface portion of a test tool into the first culture medium for a second predetermined period of time, said surface portion being coated by elemental heavy metal, respectively; removing said test tool from said first culture medium and optionally rinsing the test tool; contacting a second culture medium with the surface portion coated by elemental heavy metal of said test tool removed in the previous step; and identifying the test bacterium as being capable of binding elemental heavy metal from growth of the test bacterium in said second culture medium.

The invention provides an assay for identifying a bacterium capable of binding elemental heavy metal, comprising the following steps: cultivating a test bacterium in a suitable first culture medium; immersing at least a surface portion of a test tool into the first culture medium for a second predetermined period of time, said surface portion being coated by elemental heavy metal, respectively; removing said test tool from said first culture medium and optionally rinsing the test tool; contacting a second culture medium with the surface portion coated by elemental heavy metal of said test tool removed in the previous step; and identifying the test bacterium as being capable of binding elemental heavy metal from growth of the test bacterium in said second culture medium.

Presently described are engineered microbes modified such that the surface of the microbe contains one or more rare earth element (REE) binding ligands, as well as methods of use thereof.

Presently described are engineered microbes modified such that the surface of the microbe contains one or more rare earth element (REE) binding ligands, as well as methods of use thereof.

The present disclosure provides a method for wet removal of sulfur dioxide by silicate bacteria-enhanced pulp. The method includes: treatment of ore waste residue, activation and domestication of silicate bacteria, preparation of pulp, removal of sulfur dioxide, and resource utilization of a desulfurization product. The present disclosure combines flue gas desulfurization with resource utilization of the ore waste residue, and improves a desulfurization efficiency of the method by the pulp and a utilization rate of ore waste residue resources through silicate bacteria. The present disclosure has a high desulfurization efficiency, simple production process, and low cost, and realizes the recycling of resources such as the ore waste residue, the sulfur dioxide, and silicon. The present disclosure has obvious economic and environmental benefits and broad prospects for use.