US841721A - Process of treating ores. - Google Patents

Description

" TED s'r- 'r PATEN; FFlQE.

JOHN a. RYAN, or PORTLAND, OREGON;

PROCESS oer-searing ones.

- Specification of Letters Patent.

Patented Jan. 22, 1907.

Application filed March 1, 1906. Serial No. 303.664.

To all whom it 171,041 concern:

Be it known that I, JOHN H. RYAN, a citihzen of'the United States, residing at Portland, in the county of Multnomah and State of Oregon, have invented certain new and useful Improvements in Processes of Treating Ores, of which the following is a specification.

This invention is a process'of treating ores,

and is more -par-ticularly adapted for the treatment of, such ores as contain metalsyleldlng soluble sulfates or sulfites, often containing also the precious metals. Of such ores those containing co per, or copper and nickel, or nickel and coba t,,or cobalt, may be considered. as types.

Such ores generally occur in combination 'WltllSlllflll or arsenic, and 1f they are subjected to a oasting operation of the usual character there results not only a loss of' a portion of the (precious metals, but thecopper, nickel, an

, they are subsequently leached;

the same in all cases. thenground to pass a standard screen of sixty to one hundred and twenty mesh.'that is, t e ore isground to such degree of fineness as is usually employed in preparation.

I have discovered that by proceeding in a definitemanner as hereinafter set forth the extraction of the metal values and their 're "covery may be'effected with substantially quantitative results.

The'preliminary treatment is substantially The ore is crushed and ufoi'leachingr T e fine ore 'is s read upon the hearth of a muffle-roaster an constantly agitated thereon and is maintained at a itemperature not exceeding 300 Fahrenheit for a-definite period, usually about one hour,

until reaction has substantially ceased. It is then further heated to a temperature not exceeding-450 Fahrenheit, this temperature being likewise maintained for about the same period with constant rabbling of the ahren heit or less for a further period of about one hour, when it .is raised to approximately 1,000 Fahrenheit, this temperature, corresppnding to a'r'ed-heat, being maintained for a out an hour? or until the volatile im urities are entirel eliminated. The ore is t en dis-.- charged w ile still hot-into a suitably dilute solution of sulfuric or sulfurous. acid for the preparatienggofQthej'sulfate or sulfite solution.

4 cobalt are transformed into such diflicultly-soluble compounds that a very lmperfect extraction isv afforded when r he temperature is then' a ain increased and is maintained at 800 Such acid solution is preferably prepared from the gases derived from the roasting in known manner.

I do not desire to restrict myself to the :00

number of successive heating stages above mentioned norto any 1precise degree of temperature nor period 0 stages, for, as will be understood, the conditions are subject to some variation in actime for the several cordance withthe character of the ore. I

have found it essential, however, to the best results that the roasting should occur in successive stages and that the temperature should be maintained approximately constant during each of said stages. I have also found it to be desirable that during eachv sta e the temperature should be maintained until the volatilization or separation of impurities has substantially ceased. As above stated, the metals after such treatment are found to be soluble in the acid solvents used stant temperature conditions maintained by this roaster in I manipulation of hot and cold air inlets' for a definite time before being transferred to the shelf below, where the treatment is contin ued at a suitable higher temperature. In

this manner the ore is transferred from shelf to shelf and rabbled' at prbgressively-increasing tem erature and isfinally discharged into the leac ng-vat.

Inthe case of ores containing nickel or cobalt it is advantageous to add to the ores before conveying the same to the roasting furnace about 2 3 er cent. of sodium chlorid. The roasting 1s conducted with the same precautions as above described, and the subsequent'leachin is effected with the same solvents. The leac ing is preferably effected in a continuous manner, the solvent being circulated successively through the leachingtank and through a suitable precipitating ap-' paratus for the metal. The initial temperature of the leaching solutions should be not less than Fahrenheit, and where electrolytic precipitation is employed as herein described the deposition should be effected at a temperature not below 80 Fahrenheit. After the metals yielding soluble sulfates or sulfites are extracted the'tailings are treated for the recovery of precious metals, if such be present. For this urpose they are neutrali zed by lime or y the hydroxid or carbonate of sodiu'm or potassium and are then subjected to the solvent action of a cyanid or other solution, thegold and silver being recovered in the usual manner.

In some cases, and more particularly when treating cobalt ores containing gold and silver, I find it advantageous to regrind the tailings Wet, as the precious metals are then more readily and completely dissolved.

The treatment of the metal-bearing solutions obtained by leaching must be varied somewhat in accordance with the character of the ore. For copper ores .the copperis preferably electrodeposited in a continuous depositing-tank, using insoluble anodes; the tank being preferabl of the character de scribed in my co en g pplication, Serial Nogsoacce, filed vlarc'h 1, 1906.

In case iron is present in the ores it passes quantit- 'ust su cien-t for the precipitation of the 1110 rel, thereafter electrodepositing the cobalt from the clea'rsolution. The rnck'el may be recovered in any suitable manner, as by solution of the hydroxid and electrodeposition of the metal or by conversion of the same into metal anodes suitable for electrolytic refining. 'I

In the case of ores containing-copper and nickel the iron is generally present as magnetic oxid, and after the copper and'nickel havev been leached out the tailings may be dried, reground, and passed thro ha magnet-ic'separator for the recovery 0 the iron. 'fhejpure magnetic oxid-so obtained may be subsequently smelted, preferably utilizing the electric power Where available.

I'claim 1. The process of treating ore preparatory to leaching which consists in roasting the ore in successive ,stages at progressively higher temperatures, the ore being heated at each stage for an optional time, and maintaining itin agitation throughout the roasting operation, substantially as described.

, 2. The process of treating ore preparatory to leaching which consists in reducing the ore to a fine state of division, then roasting the 'ore in successive stages at pro essively higher temperatures, the ore be ng eated at each stage for an optional time, and main? taining it in agitation throughout the roast ing operation, substantially as described.

' 3. he process of treating ore preparatory to leaching'whichconsists in mlxing therewith sodium chlorid, and then roasting the ore in successive stages at pr higher tem eratures, the ore being eated at each st e or an optional time, substantially asdescri ed. 4

4. The process of treating ore containing nickel or cobalt preparatory to leaching which consists mixing therewith sodium chlorid, then roasting the ore in successive stages at progressively higher temperatures,

' the ore-being heatedat each stage for an optional time, and maintaining the ore in-agitastantiallyas described.

5. The process oftreating sulfid ore which tion throughout-the roasting operation, sub-.

consists in grinding the ore to the degree of fineness requisite for leaching, then roasting the ore in successive stages at pro essively higher tem ratures, the ore bemgheated at each stage or an optional tithe, maintaining the ore in agitation throughout the" roasting operation, convertin the roaster-gases into a solvent solution, an discharging the roasted ore while still in a heated state into the solution so prepared, substantially as described.

In testimony whereof I aflix my signature in presence of two witnesses.

'- JOHN H. RYAN.

Witnesses:

C. W. FOWLER, J. B. HILL.