Ore flotation and flotation reagent



Patented Mar. 6, 1934 ORE FIZOTATION AND FLOTATION REAGENT Ira 11. Derbyand Orin n. Cunningham, Indianapolis, Ind, assignors to Peter C. Reilly,

Indianapolis, Ind.
No Drawing..- Application March 2, 1931, Serial No. 519,681

14 Claims. (Cl. 209-166) The present invention relates to certainimprovements in the froth flotation process of minerals by the use ofnitrogenous base salts of certain organic thiophosphoric acid compoundswhich contain naphthalene, or analogous substances, as part of themolecular structure, as herein set forth. The invention embraces boththe product and the method of making the same, as well as the use of theproduct in the froth w flotation of minerals.
More particularly our invention is based upon the discovery thatmaterials having flotation value can be prepared by a three-stepreaction, in which a (preferably polynuclear) hydrocarwbonac'eous'substance such as naphthalene is made to react withphosphorus pentasulfide (or with phosphorus and sulfur) to form anaphthalene thiophosphoric acid anhydride intermediate product which inturn is caused to react with go phenol (or certain other substancesmentioned below), to produce a naphthalene thiophosphoric acid compoundwhich in turn is combined with an organic nitrogenous base to form acompound which may be described as a nitrogenous base salt of anaphthalene thiophosphoric acid compound.
The organic thiophosphoric acid compounds that can be employed in thepreparation of the flotation reagent according to the present inventionare completely described and specifically claimed in application SerialNo. 199,625, which has issued as U. S. Patent 1,772,386, filed June 17,1927, and dated August 5, 1930. The present case, however, relates tothe compounds of the acid as specified in said patent, or the analoguesthereof with the nitrogen bases hereinafter more fully set forth.
 While the naphthalene thiophosphoric acid anhydride compound is thepreferred intermediate in the preparation of the flotation reagent ofthe present invention, other hydrocarbonaceous substances may beemployed equally well, such as, for example, the coal tar crystallinesubstances acenaphthene, anthracene, carbazol,

phenanthrene, or mixtures of the same as they normally occur in therefining-of tar, or a coal tar oil consisting essentially ofhydrocarbonaceous substances. We use the term hydrocarbonaceoussubstance hereinafter to cover the group of substances mentioned in thisparagraph.
As phenol equivalents to combine, for example, with thenaphthalenethiophosphoric acid anhydride compound, we give the followingclassification of compounds:

(a) Phenolic compounds. such as carbolic acid,

cresols, xylenols, tanacids or closely related homologues of the same.
(b) The hydrogenated phenolic compounds.
(0) The aliphatic alcohols, containing from one up to five carbon atomssuch as for examso ple, ethyl alcohol, n-propyl alcohol, n-butylalcohol, n-amyl alcohol as well as isomeric alcohols of the same.
(d) The aliphatic and aromatic mercaptols such as the ethyl, propyl,etc. mercaptols, phe- 5 nyl mercaptol or closely related homologues ofthe same.
Substances as specified in the above classification may be embraced inthe term a phenol-like substance in that said substances all react in asimilar or analogous manner in the present process, and structurallythey may be regarded as ROH (or RSH) the OH or SH group containing alabile hydrogen atom.
The naphthalene thiophosphoric acid compounds, for" example, obtained bythe reaction of the naphthalene thiophosphoric acid anhy dride compoundwith the compounds of the above classification are excellent flotationreagents of themselves as disclosed in our application Ser. 30 No.199,625, above referred to.
When, however, these thiophosphoric acid compounds are combined withorganic nitrogenous bases to form nitrogenous base thiophosphoric acidsalts, a flotation reagent is obtained which, 5 on some ores, issuperior to the original thiophosphoric acid compound obtained;particularly is it more effective on oxidized ores.
 We give the following classification of the nitrogenous bases that maybe employed in the production of the nitrogenous base thiophosphoricacid salts of our invention, namely:

(a) Aliphatic amines such as, for example, the ethyl, propyl, butyl, andamyl amines or closely related homologues of the same.
(b) Aromatic amines such as, for example, aniline, methyl or ethylaniline, dimethyl or diethyl aniline, toluidine, alpha-naphthylamine,benzyl amine or closely related homologues of the same.
(c) Pyridine bases such as, for example, pyridine, quinolin, or themixed pyridine bases obtained from coal tar oils.
Substances which are included in the foregoing classification arehereinafter embraced in the term an organic nitrogenous base. Such basesare of course capable of combining with acids, including the specificacids above referred to, containing an organic thiophosphoric acid groupno yellow phosphorus with and containing one of the hydrocarbonaceoussubstances above noted.
These nitrogenous base salts of an organic thiophosphoric acidcomprising hydrocarbonaceous substances, such as for example,naphthalene, as a part of the molecular structure, possess a very highselective or collecting power for metalliferous materials in frothflotation operations; particularly are they effective on sulfide andoxide ores. A suitable frothing agent such as pine oil or tar acids maybe employed in conjunction with the above reagents, although theypossess som frothing action of themselves.
It is not necessary that chemically pure substances be used in thepreparation of the above reagents, since unrefined products can beemployed with metallurgical results practically as good as thoseobtained with pure chemicals.
 -We give the following examples, but we do not restrict the inventionthereto:-

In the preparation of the flotation reagent of our invention, the firststep in the process consists in the preparation of the naphthalenethiophosphoric acid anhydride intermediate as follows:

Fifty (50) parts of pure or partially refined naphthalene and 37.9 partsof sulfur are melted together and heated to 200 C. or thereabout withstirring. At this temperature the sulfur and naphthalene will form ahomogeneous solution. To this solution, preferably in an inertatmosphere, is then slowly added 12.1 parts of melted stirring. The rateof addition of the phosphorus may be conveniently governed by thetemperature of the reaction mixture, regulating the flow of phosphorusso that said temperature does not rise above a certain temperaturelimit, "such as 210 When the addition of the phosphorous is complete thereaction of the phosphorus and sulfur to form phosphorus sulfide may besaid to be complete. The process then consists in bringing about thereaction of the phosphorus sulfide thus formed with the naphthalene bymaintaining the temperature of the reaction mixture at 210 C., orthereabout, until there is a loss of 6.5 parts, or thereabout, of sulfuras hydrogen sulfide, which may require from one to two hours time. Theproduct obtained is an amber colored resinous material, liquid at 100 C.or thereabout (or it may separate as a crystalline product) which may bedescribed as a naphthalene thiophosphoric acid anhydride compound.
Instead of starting with-phosphorus and sulphur. 43.5 parts ofphosphorus pentasulfide (Pass) and 6.5 parts of sulfur may be combinedwith 50 parts of naphthalene with equally good results.
Although an excess of sulfur over phosphorus pentasulfide is notessential, we prefer to use a small excess, not limiting ourselves,however, to the amount employed above, nor do we limit ourselves to theabove specified temperature and time.
 We have found it convenient to use an excess of naphthalene over thatrequired for the reaction with phosphorus pentasulflde, the excess ofnaphthalene serving as a convenient solvent medium for the naphthalenethiophosphoric acid anhydride formed.
Working under substantially the same conditions, the naphthaleneof theabove preparation may be replaced with an equal weight (50 pts.)

ing essentially of a hydrocarbonaceous substance,

the organic thiophosphoric acid anhydride comare slowly mixed with 50parts of anhydrous tar acid, the temperature, during the mixing, notbeing allowed to rise above 10 C. or thereabout.
The reaction takes place readily and may be con-- sidered to be completewhen the mixture has become homogeneous. The product is a syrupy liquid.The amount of tar acid used may be varied arbitrarily so long as thereis suflicient present for the reaction, it being preferable to useenough in excess to leave the reaction product in a liquid condition,any excess tar acid also serving as a very good frothing reagent.
In the above preparation we do not limit ourselves to a reactiontemperature, but may use a.
little higher temperature such as 125 C. to bring about a completecombination of these substances.
In like manner the various substances listed above as phenol equivalentsmay be combined with the naphthalene thiophosphoric acid anhydridereagent, namely, alcohols, and aliphatic and aromatic mercaptols.
To produce the final product-of the present invention '80 parts, orthereabout, of the reaction product from the preceding example arecombined with about 20 parts of aniline, toluidine, alpha-naphthylamine,coal tar pyridine bases, etc. at 70 C. or thereabout. The nitrogenousbase is preferably added slowly to the tar acid naphthalenethiophosphoric acid preparation with stirring. The reaction may beconsidered to .be complete as soon as the last of the nitrogenous basehas been added.
 The product produced (anilin being employed in the proportions and underthe conditions given in this example) is an amber colored syrupy liquid.When using different proportions it is possible to make semi-solid, orsubstantially solid products. The formula of the anilin compound orthereabout, of pure or partially refined ace-.
naphthene, carbazol, anthracene,- phenanthrene or mixtures of the sameor a. coal tar oil consistproduced in accordance with example may be We,of course, do not restrict the invention to any theoretical formula, butthe above is what we believe may be the correct one. We give thisformula by way of illustration of one specific formula falling withinthe scope of the invention, believing said formula to be accurate.
v The general procedure outlined in the above examples may be applied inchemically 'combining PzSs with any of the various classes of compoundsoutlined in the early part of the specifications to form nitrogenousbase salts of certain organic thiophosphoric acid compounds as hereindisclosed, these reactions taking place readily at the temperaturesindicated, or thereabout, in the presence preferably of an excess of thereacting organic liquid substance (or other suitable inert organicliquids) to serve as a solvent.
In the froth flotation of ores by the use of the above products ascollecting agents the said products, although possessing some frothingaction, may require the use of a suitable frothing agent such as, forexample, pine oil, terpineol, cresylic acid or the like. The saidreagents and frothing agents may be introduced into the pulp in anyconvenient manner and at any appropriate stage preceding or during theflotation operation.
 Thus, for example, it may be mixed with the ore pulp in a tube mill orother device in which the ore is being pulverized; and the amount ofsaid reagent may be varied between wide limits depending upon the natureof the ore under treatment. Good results are obtained in many cases bythe use of 0.1 to 0.2 pound of the reagent per ton of ore.
The pulp is then subjected to the ordinary aeration or froth flotationoperation, producing a foam carrying the mineral from the ore. Theflotation can be conducted in any type of froth flotation apparatus andin a neutral, alkaline or acid circuit, as desired.
As illustrative of the practice of the invention, 0.15 pound per ton ofore of the toluidine salt of the tar acid naphthalene thiophosphoricacid compound was employed in conjunction with the froth flotation of adifiicultly fioatable copper sulfide bearing ore (containing someoxidized copper mineral) of the Phelps-Dodge Corporation, together witha 0.1 pound of terpineol as a frothing agent and an alkaline circuit(2.0 pound of lime perton). A recovery of or thereabout, of the copperbearing mineral .was obtained, together with a high grade concentrate.
The same reagent employed in conjunction with the flotationconcentration of Utah Copper Company ore, under substantially the sameconditions, gave a recovery of better than 90% of the copper bearingmineral in the form of a high grade concentrate.
This application is a continuation in part of our application SerialNumber 96,061 filed March 19th, 1926.
We claim:

1. A process which comprises floating ore ma terial in the presence ofan organic nitrogenous base salt of a hydrocarbon compound of an organicthiophosphoric acid.
2. The froth flotation of metalliferous material while in the presenceof an organic nitrogenous base salt of a hydrocarbon compound of anorganic thiophosphoric acid.
 3. 'The froth flotation of metalliferous material while in the presenceof an organic nitrogenous base salt of an organic thoiphosphoric acidunited with a hydrocarbon as a part of the molecular structure.
4. The froth flotation of metalliferous materials while in the presenceof an aniline salt of an organic thiophosphoric acid united with ahydrocarbon as a part of the molecular structure.
5. The froth flotation of metalliferous materials while in the presenceof an aromatic amine salt of an organic thiophosphoric acid united witha hydrocarbon as a part of the molecular structure.
6. The froth flotation of materials while in the presence of anaphthylamine salt of an organic thiophosphoric acid united with ahydrocarbonaceous substance as a part of the molecular structure.
7. The froth flotation of materials while in the presence of a pyridinebase salt of an organic thiophosphoric acid united with ahydrocarbonaceous substance as a part of the molecular structure.
8. Froth flotation of ores while in the presence of an organicnitrogenous base salt of an organic thiophosphoric compound ofnaphthalene combined with an alcohol.
9. Froth flotation of ores while in the presence of an organicnitrogenous base salt of an organic thiophosphoric compound ofnaphthalene combined with a phenol.
10. Froth flotation of ores while in the presence of an organicnitrogenous base salt of an organic thiophosphoric compound ofnaphthalene combined with a tar acid.
11. A new flotation reagent comprising an organic nitrogenous base saltof an organic thiophosphoric acid compound united with a hydrocarbon asan essential part of its composition.
 12. A new flotation reagent comprising the reaction product ofnaphthalene thiophosphoric acid anhydride; with a substance selectedfrom the herein described group of compounds, ((1.) phenolic compounds,(11) hydrogenated phenolic compounds, (0) aliphatic alcohols containingfrom 1 to 5 carbon atoms, and (d) the aliphatic and aromatic mercaptolsand their homologues; and with an organic nitrogenous" base.
13. A new flotation reagent comprising the reaction product ofnaphthalene thiophosphoric acid anhydride, with tar acid; and with anorganic nitrogenous base.
14. A process which comprises reacting with phosphorus and sulfur on ahydrocarbonaceous substance capable of forming a thiophosphoric acidcompound of said hydrocarbonaceous substance, reacting on the latterwith a phenol-like substance to form an organic thiophosphoric acidcompound of said hydrocarbonaceous substance, and reacting on the latterwith an organic nitrogenous base to .form an organic nitrogenous basesalt of said last mentioned acid, the latter 135 being capable of use asa flotation reagent.
IRA H. DERBY. CRIN D. CUNNINGHAM.
