Process for leaching particulate solid materials

A leaching process which is useful for leaching a particulate solid material comprising an extractable portion and a non-extractable portion, said extractable portion being of greater density than said non-extractable portion whereby extraction is accompanied by an increase in the buoyancy of said particulate solid material, said process comprising the steps of:

• (1) introducing said particulate solid material and a liquid solvent to an extraction zone,
• (2) subjecting said liquid solvent within said extraction zone to controlled agitation to suspend said particulate solid material therein and effect segregation of particles thereof in relation to their propensity to settle,
• (3) maintaining said liquid solvent in contact with said suspended particulate solid material within said extraction zone for a time sufficient to leach extractable material therefrom,
• and (4) selectivley withdrawing, on the basis of said segregation, more buoyant particles of said particulate solid material from said extraction zone while leaving less buoyant particles within said extraction zone.

A leaching process which is useful for leaching a particulate solid material comprising an extractable portion and a non-extractable portion, said extractable portion being of lesser density than said non-extractable portion whereby extraction is accompanied by a decrease in the buoyancy of said particulate solid material, said process comprising the steps of:

• (1) introducing said particulate solid material and a liquid solvent to an extraction zone,
• (2) subjecting said liquid solvent within said extraction zone to controlled agitation to suspend said particulate solid material therein and effect segregation of particles thereof in relation to their propensity to settle,
• (3) maintaining said liquid solvent in contact with said suspended particulate solid material within said extraction zone for a time sufficient to leach extractable material therefrom,
• and (4) selectively withrawing, on the basis of said segregation, less buoyant particles of said particulate solid material from said extraction zone while leaving more buoyant particles within said extraction zone.

A leaching process which is useful for leaching a particulate solid material comprising an extractable portion and a non-extractable portion, said process comprising the steps of:

• (1) introducing said particulate solid material and a liquid solvent to at least one stage of a series of stages in each of which said particulate solid material is contacted with said liquid solvent,
• (2) subjecting said liquid solvent in each of said stages to controlled agitation to suspend said particulate solid material therein and effect segregation of particles thereof in relation to their propensity to settle,
• (3) maintaining said liquid solvent in contact with said suspended particulate solid mateiral within each of said stages for a time sufficient to leach extractable material therefrom,
• (4) selectively withdrawing, on the basis of said segregation, particles of said particulate solid material from each stage of said series except the final stage and introducing said particles to the next successive stage of said series,
• and (5) withdrawing from the final stage of said series particulate solid material from which substantially all of said extractable portion has been extracted.

A leaching process which is useful for leaching a particulate solid material comprising an extractable portion and a non-extractable portion, said extractable portion being of greater density than said non-extractable portion whereby extraction is accompanied by an increase in the buoyancy of said particulate solid material, said process comprising the steps of:

• (1) introducing said particulate solid material and a liquid solvent to at least one stage of a series of stages in each of which said particulate solid material is contacted with said liquid solvent,
• (2) subjecting said liquid solvent in each of said stages to controlled agitation to suspend said particulate solid material therein and effect segregation of particles thereof in relation to their propensity to settle,
• (3) maintaining said liquid solvent in contact with said suspended particulate solid material within each of said stages for a time sufficient to leach extractable material therefrom,
• (4) selectively withdrawing, on the basis of said segregation, more buoyant particles of said particulate solid material from each stage of said series except the final stage while leaving less buoyant particles within such stage and introducing said more buoyant particles to the next successive stage of said series,
• and (5) withdrawing from the final stage of said series particulate solid material from which substantially all of said extractable portion has been extracted.

A leaching process which is useful for leaching a particulate solid material comprising an extractable portion and a non-extractable portion, said extractable portion being of lesser density than said non-extractable portion whereby extraction is accompanied by a decrease in the buoyancy of said particulate solid material, said process comprising the steps of:

• (1) introducing said particulate solid material and a liquid solvent to at least one stage of a series of stages in each of which said particulate solid material is contacted with said liquid solvent,
• (2) subjecting said liquid solvent in each of said stages to controlled agitation to suspend said particulate solid material therein and effect segregation of particles thereof in relation to their propensity to settle,
• (3) maintaining said liquid solvent in contact with said suspended particulate solid material within each of said stages for a time sufficient to leach extractable material therefrom,
• (4) selectively withdrawing, on the basis of said segregation, less buoyant particles of said particulate solid material from each stage of said series except the final stage while leaving more buoyant particles within such stage and introducing said less buoyant particles to the next successive stage of said series,
• and (5) withdrawing from the final stage of said series particulate solid material from which substantially all of said extractable portion has been extracted.

A leaching process which is useful for leaching a particulate solid material that comprises extractable and non-extractable portions of different density, whereby extraction is accompanied by a change in the buoyancy of said particulate solid material, said process comprising the steps of:

• (1) introducing said particulate solid material and a liquid solvent to at least one stage of a series of stages in each of which said particulate solid material is contacted with said liquid solvent,
• (2) subjecting said liquid solvent in each of said stages to controlled agitation to suspend said particulate solid material therein and effect segregation of particles thereof in relation to their propensity to settle,
• (3) maintaining said liquid solvent in contact with said suspended particulate solid material within each of said stages for a time sufficient to leach extractable material therefrom,
• (4) selectively withdrawing, on the basis of said segregation, from each stage of said series except the final stage a slurry comprised of liquid solvent rich in either more buoyant or less buoyant particles of said particulate solid material and introducing said slurry to the next successive stage of said series,
• and (5) withdrawing from the final stage of said series particulate solid material from which substantially all of said extractable portion has been extracted.

A leaching process which is useful for leaching a particulate solid material comprising an extractable portion and a non-extractable portion, said extractable portion being of greater density than said non-extractable portion whereby extraction is accompanied by an increase in the buoyancy of said particulate solid material, said process comprising the steps of:

• (1) introducing said particulate solid material and a liquid solvent to at least one stage of a series of stages in each of which said particulate solid material is contacted with said liquid solvent,
• (2) subjecting said liquid solvent in each of said stages to controlled agitation to suspend said particulate solid material therein and effect segregation of particles thereof in relation to their propensity to settle,
• (3) maintaining said liquid solvent in contact with said suspended particulate solid material within each of said stages for a time sufficient to leach extractable material therefrom,
• (4) selectively withdrawing, on the basis of said segregation, from each stage of said series except the final stage a slurry comprised of liquid solvent rich in more buoyant particles of said particulate solid material and introducing said slurry to the next successive stage of said series,
• and (5) withdrawing from the final stage of said series a particulate solid material from which substantially all of said extractable portion has been extracted.

A leaching process which is useful for leaching a particulate solid material comprising an extractable portion and a non-extractable portion, said extractable portion being of lesser density than said non-extractable portion whereby extraction is accompanied by a decrease in the buoyancy of said particulate solid material, said process comprising the steps of:

• (1) introducing said particulate solid material and a liquid solvent to at least one stage of a series of stages in each of which said particulate solid material is contacted with said liquid solvent,
• (2) subjecting said liquid solvent in each of said stages to controlled agitation to suspend said particulate solid material therein and effect segregation of particles thereof in relation to their propensity to settle,
• (3) maintaining said liquid solvent in contact with said suspended particulate solid material within each of said stages for a time sufficient to leach extractable material therefrom,
• (4) selectively withdrawing, on the basis of said segregation, from each stage of said series except the final stage a slurry comprised of liquid solvent rich in less buoyant particles of said particulate solid material and introducing said slurry to the next successive stage of said series,
• and (5) withdrawing from the final stage of said series particulate solid material from which substantially all of said extractable portion has been extracted.

A process for the demineralization of bone in which particles of bone are leached with an acid solution to extract mineral material and yield particles of ossein similar in size and shape to said bone particles, said mineral material being of greater density than said ossein whereby said extraction is accompanied by an increase in the buoyancy of said bone particles, said process comprising the steps of:

• (1) introducing said bone particles and said acid solution to at least one stage of a series of stages in each of which said bone particles are contacted with said acid solution to extract said mineral material,
• (2) subjecting said acid solution in each of said stages to controlled agitation to suspend said bone particles therein and effect segregation thereof in relation to their propensity to settle,
• (3) maintaining said acid solution in contact with said suspended bone particles within each of said stages for a time sufficient to leach mineral material therefrom,
• (4) selectively withdrawing, on the basis of said segregation, more buoyant bone particles from each stage of said series except the final stage while leaving less buoyant bone particles within such stage and introducing said more buoyant bone particles to the next successive stage of said series,
• and (5) withdrawing from the final stage of said series particles which are substantially free of said mineral material and composed essentially of ossein.

A process for the demineralization of bone in which particles of bone are leached with an acid solution to extract mineral material and yield particles of ossein similar in size and shape to said bone particles, said mineral material being of greater density than said ossein whereby said extraction is accompanied by an increase in the buoyancy of said bone particles, said process comprising the steps of:

• (1) introducing said bone particles and said acid solution to the lowermost and uppermost compartments, respectively, of a vertical multi-compartment extraction column,
• (2) subjecting said acid solution in each of said compartments to controlled agitation to suspend said bone particles therein and effect segregation thereof in relation to their propensity to settle,
• (3) maintaining said acid solution in contact with said suspended bone particles within each of said compartments for a time sufficient to leach mineral therefrom,
• (4) passing acid solution from each said compartment except the lowermost compartment to the compartment below,
• (5) selectively withdrawing, on the basis of said segregation, more buoyant bone particles from each said compartment except the uppermost compartment and introducing said more buoyant bone particles to the next higher compartment,
• and (6) withdrawing from the uppermost compartment particles which are substantially free of said mineral material and composed essentially of ossein.