US2551197A

US2551197A - Treatment of feldspar concentrates having hydrophobic characteristics

Info

Publication number: US2551197A
Application number: US81847A
Authority: US
Inventors: Jr James A Barr
Original assignee: Armour and Co
Current assignee: Armour and Co
Priority date: 1949-03-16
Filing date: 1949-03-16
Publication date: 1951-05-01
Anticipated expiration: 1968-05-01

Description

Patented May 1, 195T TREATMENT OF FELDSPAR CONCENTRATES HAVING HYDROPHOBIC CHARACTERIS- TICS James A. Barr, Jr., Evanston, Ill., assignor to Armour and Company, Chicago, 111., a corporation of Illinois No Drawing. Application March 16, 1949, Serial No. 81,847

7 Claims. (01. 23-110) This invention relates to the treatment of feldspar concentrates having hydrophobic characteristics for removal of such characteristics. The invention is particularly useful in the removal of hydrophobic films formed on feldspar concentrate by froth flotation. .1 In the production of feldspar concentrate by froth flotation, nitrogenous compounds are employed which introduce a hydrophobic film onto the concentrate. Later, in castin operations the hydrophobic film causes frothing of a casting slip which includes such feldspar flotation concentrate. Such frothin has sometimes caused the rejection of feldspar flotation concentrate for use in the mold casting processes of the ceramic industry.

In casting operations, it is customary to form a casting slip consisting of a mixture of feldspar, quartz and clays (both primary and secondary). This material is mixed with Water and alkali to deflocculate the slip. The slip is poured into a porous mold and is left for a predetermined time. The water is drawn into the mold and minerals are built up as a body inside the mold. Later,

the mold parts are usually separated to free the cast body.

In the forming of the casting slip, as above described, it is found that the feldspar flotation concentrate, by reason of its hydrophobic film causes serious frothing.

An object of the present invention is to provide a simple method and means for removing hydrophobic film from feldspar concentrates whereby frothing does not occur in the casting slip forming step. Yet another object is to provide a simple operation whereby feldspar concentrates having hydrophobic characteristics are modified so as to no longer cause frothing in the forming of a casting slip. Other specific objects and advantages will appear as the specification proceeds.

I have discovered that by mixing a mineral having a high base exchange capacity with feldspar concentrates having such hydrophobic characteristics, the hydrophobic film is removed from the feldspar to a satisfactory degree. The organo-colloidal mineral complex can be isolated and readily removed. The process is effective with feldspar concentrates which have been treated with any nitrogenous compounds that introduce hydrophobic characteristics into the concentrates. Such nitrogenous materials producing these results include high molecular weight amines, high molecular weight amine salts derived from fatty acids, such as the amine acetate and amine hydrochloride salts. Other nitrogenous materials are glyoxalidines, rosinamine acetate, tallow trimethyl ammonium chloride, etc. It will be un-. derstood that the hydrophobic film is formed through the use of a large number of such nitrogenous compounds and presents the problem to the solution of which the process of the present invention is directed.

In carrying out my invention, the feldspar concentrate having the hydrophobic film or characteristic is treated by agitation with a small amount of a mineral having a high base exchange capacity preferably long enough for the frothing to disappear. The treating mineral and the film form a colloidal body which may be decanted or otherwise readily removed. Kaolinite and bentonite provide satisfactory treating materials. They may be-used in the proportions of from 1 to 10 pounds for each ton of concentrate being treated. I prefer to use about 2 to 5 pounds of the treating mineral per ton of concentrate.

The colloidal material containing the bentonite or kaolinite, etc., in counter-current washing is decanted from the top of the liquid body while the concentrate minerals are withdrawn from the lower portion of the body. Ready removal is effected in a hydroclassifier in which the concentrate passes through a vessel having an open bottom and in which a stream of water is introduced so as to overflow at the top. The colloidal material overflows and is thus separated from the concentrate and the recovered concentrate may then be employed in forming casting slips with no resulting frothing.

Specific examples of the process may be set out as follows:

Example I North Carolina feldspar containing Muscovite mica, biotite mica, garnet, sodium and potassium feldspars, and quartz was separated into a mica fraction, a garnet fraction, a feldspar fraction, and a quartz fraction. In the feldspar and quartz separation .35 pound of an amine acetate derived from tallow fatty acid (Armac T) was used per ton of the concentrate and also hydrofluoric acid was employed to depress the quartz. Pine oil was used to form a froth. The feldspar concentrate obtained when employed in forming a casting slip, produced frothing of the slip. To eliminate the hydrophobic film formed in the feldspar concentrate, the feldspar concentrate was agitated with 2 pounds of bentonite per ton of concentrate forlabout 5 minutes, after which the froth disappeared. The colloidal material produced by this treatment was then removed by decanting and the feldspar concentrate was washed relatively free of colloidal material. After drying, the feldspar so treated was found to be water wettable upon agitation and did not cause froth to form when aerated or mixed with other minerals to form acasting slip.

Example II In a similar treatment of feldspar in which .4 pound of amine acetate (Armac T), 0.8,pound of a hydrocarbon, .1-.2 pound of pine oil and 1-1 pounds of hydrofluoric acid per ton of feldspar concentrate was used and a hydrophobic film characteristic developed in the feldspar concentrate. Feldspar was agitated with 5 pounds of kaolinite for about 5 minutes when the froth disappeared. The material was then put-through a hydroclassifier in which the feldspar concentrate was washed free of colloidal material and the colloidal material containing kaolinite and the hydrophobic film was removed from the top of the classifier. The feldspar recovered in the above process was found to be water wettable and did not cause froth when aerated or mixed with other minerals to form a casting slip.

Example III In a treatment of feldspar with amine hydrochloride derived from tallow fatty acid in percentages varying from .25 to .45, a hydrophobic film was introduced into the feldspar concentrate. The concentrate was treated with varying amounts of bentonite and kaolinite between 2 and 5 pounds per ton of concentrate and agitation kept up until froth disappeared. The resulting colloidal material was removed and'the washed feldspar concentrate was found to be water Wettable and did not cause frothing in the forming of the casting slip.

The operation involves very little expense because of the low amount of treating mineral required and because the colloidal material is removed so readily in a washing or desliming operation normal to milling operations.

While in the foregoing specification, I have set out steps of the process in considerable detail for the purpose of illustrating embodiments thereof, it will be understood that such detail may be varied widely by those skilled in the art without departing from the spirit of my invention.

I claim:

1. In a process for removing hydrophobic film from feldspar concentrates treated with filmforming nitrogenous material in froth flotation,

the steps of agitating the feldspar concentrates in water with a mineral having a high base exchange capacity until frothing disappears, and removing the resulting colloidal material.

2. In a process for removinghydrophobic film from feldspar concentrates treated with hydrophobic-film-forming nitrogenous materials, the

steps of agitating the feldspar concentrates in water with a mineral having a high base exchange capacity until the frothing disappears, and then removing the resulting colloidal material.

3. In a processfor removing hydrophobic film produced in feldspar concentrates by the action of treating nitrogenous materials, the steps of agitating the feldspar concentrates in water with a. small amount of mineral having a high base exchange capacity until the frothing disappears and a colloidal body is produced consisting of said material and said. film, and decanting the i colloidal-material.

4. In a process for removing hydrophobic film from feldspar concentrates produced by nitrogenous treating materials, the steps of agitating the feldspar concentrates in water "with ;.from about 2 to 5 pounds of a mineral having a high base exchange capacity per .ton of concentrate, and removing the resulting colloidal material.

5. In a process for removing hydrophobic film from feldspar concentrates in which such film is produced through the use of nitrogenous treating materials, the steps of agitating the feldspar concentrates in Water with about 2-5 pounds of bentonite per ton of concentrate, and removing the resulting colloidal material.

6. In a process for removing hydrophobic film from feldspar concentrates in which such film is produced through the use of nitrogenous treat- No references cited.

Claims

1. IN A PROCESS FOR REMOVING HYDROPHOBIC FILM FROM FELDSPAR CONCENTRATES TREATED WITH FILMFORMING NITROGENOUS MATERIAL IN FROTH FLOTATION, THE STEPS OF AGITATING THE FELDSPAR CONCENTRATES IN WATER WITH A MINERAL HAVING A HIGH BASE EXCHANGE CAPACITY UNTIL FROTHING DISAPPEARS, AND REMOVING THE RESULTING COLLOIDAL MATERIAL.