Patent EA-001697-B1 (EA)
Title: Method for phytomining of nickel, cobalt and other metals from soil
Inventor: CHANEY RUFUS L
IPC: C22B23/00
Filed: 1997-06-20
Abstract: 1. A method of recovering nickel from soil, comprising: cultivating Alyssum plants in soil containing nickel, under conditions sufficient to permit said Alyssum to accumulate nickel from the soil in above-ground tissues of said Alyssum; harvesting said Alyssum as biomass materials after accumulation of nickel from the soil, and; recovering the nickel from said harvested biomass materials, wherein said soil is conditioned by maintaining the pH of the soil at within a range of 4.5 to 6.2. 2. The method of Claim 1, wherein said soil, has an exchangeable calcium concentration and an exchangeable Mg concentration, and wherein the exchangeable calcium concentration is managed such that it has a value lower than 20% of the exchangeable Mg concentration, adding ammonium-containing fertilizer to said soil and adding chelating agents to said soil. 3. The method of Claim 1, wherein said metal is recovered by drying and combusting, said harvested biomass materials, to oxidize and vaporize organic materials present. 4. A method of recovering nickel from soil, comprising: cultivating Alyssum plants in soil containing nickel, under conditions sufficient to permit said Alyssum to accumulate nickel from the soil in above-ground tissues of said Alyssum such that at least 2.5% of the air-dried above-ground tissue of said Alyssum is nickel; harvesting said Alyssum as biomass materials after accumulation of nickel from the soil, and; recovering the nickel from said harvested biomass materials. 5. 'The method of Claim 4, wherein said soil is conditioned by maintaining the pH of the soil at within a range of 4.5 to 6.2. 6. The method of Claim 5, wherein said soil has an exchangeable calcium concentration and an exchangeable Mg concentration, and wherein the exchangeable calcium concentration is managed such that it has a value lower than 20% of the exchangeable Mg concentration. 7. The method of Claim 6, wherein ammonium-containing fertilizer is added to said soil. 8. The method of Claim 7, wherein chelating agents are added to said soil. 9. A method of recovering nickel from soil, comprising: cultivating Alyssum plants in soil containing nickel, under conditions sufficient to permit said Alyssum to accumulate nickel from the soil in above-ground tissues of said Alyssum, wherein said soil has an exchangeable calcium concentration and an exchangeable Mg concentration and wherein the exchangeable calcium concentration is managed such that it has a value lower than 20% of the exchangeable Mg concentration; harvesting said Alyssum as biomass materials after accumulation of nickel from the soil, and; recovering the nickel from said harvested biomass materials. 10. The method of Claim 1, wherein said Alyssum plants are selected from the group consisting of A. murale, A. pintodasilvae, A. heldriechii, and mixtures thereof. 11. the method of Claim 4, wherein said Alyssum plants are selected from the group consisting of A. murale, A. pintodasilvae, A. malacitanum, A. lesbiacum, A, fallacinum, A. argentum, A. bertolonii, A. tenium, A. heldriechii, and mixtures thereof. 12. The method of Claim 9, wherein said Alyssum plants are selected from the group consisting of A. murale, A. pintodasilvae, A. malacitanum, A. lesbiacum, A. fallacinum, A. argentum, A. bertolonii, A. tenium, A. heldriechii, and mixtures thereof.