Claims
- 1. In a froth flotation process for beneficiating an ore containing at least one metal mineral comprising slurrying sized particles of ore in an aqueous medium, conditioning said slurry with effective amounts of a frothing agent and a collector for said at least one metal mineral respectively, and subjecting said conditioned slurry to froth flotation, the improvement comprising, employing, as the collector at least one compound of the formula: ##STR12## wherein R is substituted or unsubstituted C.sub.1 -C.sub.12 alkyl, C.sub.5 -C.sub.7 cycloalkyl, C.sub.8 -C.sub.12 aralkyl or C.sub.6 -C.sub.12 aryl radical and X is oxygen or sulfur.
- 2. A process according to claim 1 wherein R is a C.sub.1 -C.sub.12 alkyl.
- 3. A process according to claim 1 wherein R is isobutyl.
BACKGROUND OF THE INVENTION
This is a divisional of co-pending application Ser. No. 97/409,919 now U.S. Pat. No. 4,929,393) filed on May 22, 1989 which in turn, is a divisional of application Ser. No. 97/309,572, filed on Feb. 13, 1989 now U.S. Pat. No. 4,855,507.
The reaction of primary phosphines and aldehydes to give a variety of products depending upon the nature of the substituent of the primary phosphine, the type of aldehyde and the presence of acid, is known. For example, primary aromatic or aliphatic phosphines react with formaldehyde in the presence of aqueous hydrochloric acid to give hydroxymethylphosphonium salts (Angew Chem. 72 211 [1960]); ##STR1##
Phenyl phosphine and (a) acetaldehyde or (b) benzaldehyde, in the presence of hydrochloric acid, is reported to give (a) phenyl bis (alpha-hydroxyethyl) phosphine and (b) phenyl bis(alpha-hydroxybenzyl)phosphine (CA 57:4692e [1962]); ##STR2## while phenylphosphine and isobutyraldehyde, in hydrochloric acid solution, gives an alpha-hydroxyalkyl phosphine hydrochloride (Tetrahedron 18, 1231 [1962]). ##STR3##
Furthermore, phenyl phosphine when reacted with benzaldehyde will give three different products depending on the conditions and strength of the hydrochloric acid used, ##STR4##
The reaction of phosphine and dialdehydes is reported to give spirocyclic phosphonium compounds of the formula; ##STR5## The authors noted that "attempts to prepare analogous spiran by reaction with glyoxal were unsuccessful".
The J.Org. Chem 35 (8) 2820 (1970) discloses the preparation of 2,5-dialkoxy-1,4-diphosphorinane-1,1,4,4-tetraphenyl, onium bromide, by the reaction of lithium diphenyl phosphide and chloroacetaldehyde, acetal followed by reaction with hydrogen bromide in acetic acid; ##STR6##
In CA 88:5079d [Z. Chem. 17 (10) 365 (1977] there is disclosed the preparation of 2,5-dihydroxy-1,1,4,4-tetraphenyl-1,4-diphosphorinonium dichloride by the reaction of the above phosphine with dilute hydrochloric acid; ##STR7##
U.S. Pat. No. 3,206,496 (9/14/65) discloses the preparation of 1,4,diphosphorinonium salts by the reaction of a secondary phosphine and vinyl halides; ##STR8## while U.S. Pat. No. 2,931,803 (4/5/60)teaches the preparation of fluorocarbon-containing 1,4-diphosphorinanes, 1,4-diiodides, prepared by the reaction of tetrafluoroethylene, elemental phosphorus, and iodine; ##STR9## It is further disclosed that hydrolysis of above type heterocyclic followed by oxidation results in the formation of open-chain phosphonic acids. However, all above prior art diphosphorinanes are salts and are therefore totally different from the diphosphorinanes of the instant invention, and in addition are prepared by synthetic routes entirely different than the process of this invention.
This invention relates to novel 1,4-disubstituted-2,3,5,6-tetrahydroxy-1,4-diphosphorinanes having the formula ##STR10## wherein R is a substituted or unsubstituted C.sub.1 -C.sub.12 alkyl, C.sub.5 -C.sub.7 cycloalkyl, C.sub.7 -C.sub.12 aralkyl or C.sub.6 -C.sub.12 aryl radical.
Among the preferred disubstituted tetrahydroxydiphosphorinanes conforming to Formula I are:
The disubstituted tetrahydroxydiphosphorinanes are readily prepared by the reaction of monosubstituted phosphines and glyoxal according to the equation:
The disubstituted tetrahydroxydiphosphorinanes are useful as intermediates in the production of the dioxides and disulfides thereof, i.e., those compounds having the formula: ##STR11## wherein R is as described above and X is oxygen or sulfur.
The compounds of Formula II are produced by reacting the compounds of Formula I, before or after separation and purification, as above, with hydrogen peroxide or elemental sulfur according to the equation:
This reaction with the hydrogen peroxide or elemental sulfur is conducted in the presence of a hydroxylic solvent at a temperature ranging from about 60.degree. C. to about 90.degree. C. with cooling. Useful hydroxylic solvents include water, alcohols such as tert butanol isopropanol, ethanol, and the like. Among the preferred dioxides and disulfides falling with the scope of Formula II, include:
The products, i.e. the dioxides and disulfides are crystalline and are recovered in yields generally greater than 90%. They are high melting and have a low solubility in water.
The dioxides of Formula II find use as flame-retardants for polymeric materials and both the dioxides and disulfides have been found to be useful as mining reagents for the flotation of minerals e.g. as flotation agents or collectors for cassiterite, rare earth minerals and non-sulfide associated gold ores.
The dioxide flame-retardants may be incorporated into polymers to be flame-retarded by any known procedure such as, for example, Banbury mixing, two-roll mixing, extrusion, injection molding etc in flame-retarding quantities. Usually amounts ranging from about 2 to about 20%, by weight, based on the total weight of the polymer, may be used. Ofttimes the dioxide may be incorporated during the polymer production, such as by adding it to a monomer mixture undergoing polymerization.
The polymers into which the dioxides of the present invention may be incorporated include, but are not limited to, olefin polymers such as polyethylene, polypropylene; impact styrene polymers; nylon; polyphenylene oxide; impact styrene polymer modified polyphenylene oxide; polyethylene terephthalate; polyurethanes and the like.
Preferred flame-retardant polymer dioxides are those in which the substituent (R group of Formula II) is an alkyl group of 2-6 carbon atoms, cyanoalkyl, hydroxyalkyl, aryl or aralkyl (6 to 8 carbon atoms). Specific examples of preferred phosphine oxides include, but are not limited to, 1,4-di-n-propyl-2,3,5,6-tetrahydroxy-1,4-diphosphorinane-1,4-dioxide;1,4-diisobutyl-2,3,5,6-tetrahydroxy-1,4-diphosphorinane-1,4-dioxide,1,4-bis(2-cyanoethyl)-2,3,5,6-tetrahydroxy-1,4-diphosphorinane-1,4-dioxide,1,4-bis(phenethyl)-2,3,5,6-tetrahydroxy-1,4-diphosphorinane 1,4-dioxide and the like. The phosphine oxide flame-retardants may be used alone or in combination with other flame-retardants or synergists such as titanium dioxide, ammonium polyphosphate, melamine pyrophosphate, melamine, cyanoguanidine, urea, triaryl phosphates and the like. In the case of the flame-retarding of polyurethanes, the dioxides containing reactive functional groups may be also used as reactive intermediates to form polymeric materials containing the flame-retardant phosphine oxide moiety as part of the polymer backbone. Examples of phosphine oxides useful for the preparation of flame-retarded polyurethanes include but not limited to, 1,4-bis (3-hydroxypropyl)-2,3,5,6-tetrahydroxy-1,4-diphosphorinane-1,4-dioxide; 1,4-bis (3-aminopropyl)-2,3,5,6-tetrahydroxy-1,4-diphosphorinane-1,4 -dioxide and the like.
To achieve flame-retardancy in polyurethanes, the reactive dioxides may be combined with the normally used polyols in concentrations in the range of about 2% to about 15%, by weight, based on the weight of the polyol, and reacted with isocyanates such as, for example, toluene diisocyanate (TDI) or methylene diphenyldiisocyanate (MDI) and the like to form the resultant flame-retarded polyurethane.
Various other additives may be added to the flame-retarded polymers such as plasticizers, pigments, fillers, stabilizers, i.e., antioxidants, etc., antistatic agents, dyes and the like.
As mentioned above, both the dioxides and disulfides of Formula II are useful as collectors in froth flotation procedures for beneficiating an ore containing minerals wherein liberation-sized particles of said ore are slurred in aqueous medium, said slurry is conditioned with effective amounts of a frothing agent and a mineral collector and the desired minerals are frothed by froth flotation procedures.
The following examples are set forth for purposes of illustration only and are not to be construed as limitations on the present invention except as set forth in the appended claims. All parts and percentages are by weight unless otherwise specified.
US Referenced Citations (4)
Divisions (2)
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Number |
Date |
Country |
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409919 |
May 1989 |
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| Parent |
309572 |
Feb 1989 |
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Patent Grant
4968416
