The Anaconda Company

Coproco Development Corporation

Atlantic Richfield Company

The Doe Run Company

Geological Research Corporation

Nathaniel Arbiter

Martin C Kuhn

Harold M Ray

Benjamin D Cooley

The present invention provides a process that employs both non-selective flotation and oxidative leaching of the resulting concentrates to recover an increased amount of copper from porphyry copper ores. The non-selective flotation step uses collectors and conditions, such as pH, that are conducive to the strong flotation of sulfide minerals generally. In the oxidative leach, the copper sulfide minerals in the concentrate fraction are oxidized to copper compounds, which are soluble in the leach solution. The oxidative leach includes the use of ammonia and sulfite under agitation leaching conditions to convert the copper sulfide minerals into ammonia soluble forms.

Flotation cell and method

Process for recovering copper from copper-containing material

A sequential flotation process for the separation of components of a sulfide ore selected from the group consisting of copper and lead sulfide containing ores and copper, zinc and lead sulfide containing ores in which the copper component is initially selectively floated directly from said ore by conditioning the ore with a combination of a source of bisulfite ion and causticized starch to produce a conditioned ore having a pH between approximately 5.7 and 6.5, and thereafter treating the conditioned ore with a collector selected from the group consisting of dialkyl dithiophosphates and alkyl dithiophosphinates.

Sequential and selective flotation of sulfide ores

The process of concentrating tin oxide minerals of fine particle size from material containing the same comprising the steps of forming an aqueous slurry of said material and subjecting said slurry to high intensity wet magnetic separation at a field strength and for a time sufficient to form a concentrate containing a major proportion of the tin oxide minerals originally present in the slurry.

Recovery of tin

Copper, nickel and zinc are recovered from sulfide minerals or concentrates thereof by leaching with ammonia at or near atmospheric pressure. A slurry of such minerals or concentrates in an aqueous solution containing free ammonia is passed into a closed leaching vessel or a series of such vessels into which oxygen is admitted. The slurry in such vessel or vessels is mechanically agitated with a vigor input of at least 0.05 horsepower per cubic foot and preferably while recirculating oxygen from above the slurry to well below its surface. The temperature of the slurry is maintained between 50.degree. and 100.degree. C. or up to the boiling temperature at the prevailing pressure, and the pH preferably is in the range from 9 to 11. Solids separated from the leach solution at the conclusion of such leaching operation may be releached for additional copper recovery by a similar leaching procedure in one or a series of leaching vessels. Recoveries of copper, nickel and zinc in the range from 90% to 95% can in many cases be obtained in a leaching time of 3 to 6 hours from ores and concentrates containing one or more of the minerals chalcocite, chalcopyrite, pentlandite and sphalerite. By similarly releaching the solid residue from the primary leaching operation, overall recoveries may in many cases be increased to 99%.

Recovery of copper and/or nickel and/or zinc

In the recovery of copper, nickel or zinc from sulfide ores by leaching with ammonium sulfate solution containing free ammonia in the presence of oxygen to form a leach solution containing dissolved copper, nickel or zinc ammonia sulfate complex, an alkaline metal hydroxide (preferably calcium hydroxide) is introduced into the leaching operation to precipitate the sulfate ion formed and to release ammonia combined therewith as ammonium ion.

Sulfate precipitation during oxidative ammonium leach of Cu, Ni, Zn

Copper, zinc and nickel are recovered from sulfide concentrates prepared from ores of one or more such metals by subjecting such concentrate to a leaching operation which comprises slurrying the concentrate in an aqueous solution containing ammonium sulfate and free ammonia and vigorously agitating the slurry at 50 to 80.degree. C. and below 10 psig. in the presence of free oxygen while vigorously recirculating said oxygen from above the surface of the slurry to a substantial depth below such surface. The resulting pregnant leach solution contains copper, zinc, and/or nickel in dissolved form complexed with ammonia and such solution is treated to recover the dissolved metal. The undissolved sulfidic residue from the leaching operation is subjected to a secondary flotation operation to produce a sulfide concentrate containing the metal values not dissolved in the leaching operation, and such concentrate is treated to recover such values, as by smelting or by releaching.

Recovery of metals

Lead is recovered from lead sulfide concentrates or mixed lead-zinc concentrates containing iron sulfide by forming a slurry of such concentrates in an aqueous medium containing ammonium sulfate and free ammonia, and introducing such slurry into a closed reaction vessel at a pressure not exceeding 30 psig. Oxygen also is introduced into such vessel to establish therein a partial oxygen pressure of at least a few psi, while vigorously agitating the slurry. The lead sulfide content of the concentrates thereby is converted to the form of substantially water-insoluble oxidic lead compounds, while any zinc sulfide present is dissolved. The slurry then is withdrawn from the reaction vessel and the insoluble residue is separated from the aqueous solution. The latter is treated for recovery of its zinc and ammonia content, and the residue is subjected to a froth flotation operation to form a concentrate containing substantially all the iron sulfide and a tailing containing the oxidic lead compounds. Lead is recovered from such tailing.

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Vail, AZ, United States of America

Nathaniel Arbiter