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Shafer, James Fulton Flotation on minerals 1915 BIBLIOGRAPHIC RECORD TARGET University of California at Berkeley Library Master negative storage number: 03-67.49 (national version of the master negative storage number: CU SN03067.49) GLADIS NUMBER: 184777525A FORMAT : BK AD:990922/FZB LEVEL:b BLT:am DCF:a CSC:d MOD: EL:"7 UD:030604/MAP CP:cau L:eng INT: GPC: BIO: FIC: CON: ARCV: PC: PD:1915/ REP: CPI1: FSI: ILC: IT: CUScCU 040 090 100 245 260 300 502 504 610 690 1 00 20 0 SbDISS.SHAFER.GEOL 1915 Shafer, James Fulton. Flotation on minerals. Scl915 i, 14 leaves :5c29 cm. Thesis (B.A. in Geology) -University of California, Berkeley, May 1915. Includes bibligraohical references (leaf 14). University of California, Berkeley.SbDept. of Geology and GeophysicsS$SxDissertations. Dissertations, AcademicSxUCBSxGeologySy1911-1920. Microfilmed by University of California Library Photographic Service, Berkeley, CA FILMED AND PROCESSED BY LIBRARY PHOTOGRAPHIC SERVICE, UNIVERSITY OF CALIFORNIA, BERKELEY, 94720 DATE: 7/03 REDUCTION: 10 X PM-1 3%2"x4” PHOTOGRAPHIC MICROCOPY TARGET NBS 1010a ANSI/ISO #2 EQUIVALENT 22 12 1.0 1.0 w= 22 Fee Bs we ° ie ————— III, INARI, ————— RR I= LZ [lid ps leg T THY : 5" "le | ov a a sublL elt Sit tL oft 16 18 1d 1 I El hd bi | DEXsS SKAFER ( GECL ]%215 ENACT THESIS FLOTATION ON MINERALS BY LIBRARY COPY JAMES FULTON SHAPER. Submitted for the degree of Bachelor of Arts, at the University of California, May, 1915, © F° CONTENTS. Introduction In Cold Water In Hot Water Reduced Pressure In Dilute Acid Solution In Alkaline Solutions In 0il and Water Combinations In Alkaline and Acid Solutions with 0il Rock Powders in Different Solutions In Sulfate Solutions Summary Bibliograph ® @ @®@ = oo oo ¢ OO +H =H = o = © = oS INTRODUCTION. Much has been done concerning the practical nature of flotation on metallic sulfides but little concerning the flotation of non-metals. THe following experiments were conducted in the Department of Geology under Prof. BE. 8. Larsen on the buoyancy of a wide vari- ety of minerals subjected to varying treatment. The purpose of the experiments was to study the actions of minerals under the different treatments in an effort to determine a separation of the mineral components of a rock powder by flotation. My thanks are due to Prof. Larsen under whom this thesis was taken for his suggestions, and also his aid in examining the results of the tests. I am also indebted to Kenneth A, Mickle, for extracts taken from his paper on flotation in,. The Proceedings of the Royal Society of Vietoria, Vol. XXIII, (N.S) Part 2, March,1911l. Flotation on Minerals. Many minerals, when ground to powder of 60-70 mesh, and carefully sprinkled on the surface of cold water, will float; some at once sink to the bottom. Those that float form a film on the surface of the water, each perticle of the mineral caused a distinct depdess- ion or sag about itself. If aleohol in the form of a drop on a glass rod be brought near the particles float- ing on the surface, the particles are repelled from the rod. If alcohol or ether are added to the water, the particles become wetted and sink. This is apparently a surface tension phenomenon according to K. A. Mickle in Proceedings of the Royal Society of Vietoria, Vol. XXIII, Mareh, 1911, who says: "In the case of the alco- hol on the glass rod, the vapor of the alcohol mixing with the water decreases the surface tension and increas- es the adhesion of the water for the mineral. The water wets the particle of a higher level on the side nearest the glass rod; an inclined plane is formed on the side furthest from the rod, and the particle is ap- parently repelled. Water has the greatest surface tension of all liquids, under ordinary atmospheric con- ditions, except mercury, and thus if another liquid is added to it, the surface temsion is decreased. If pulverized mineral is wetted, and covered with water, and then is exposed to the air by causing the water to run to one side of the containing vessel and the water is then brought carefully back, some of the mineral will be seen to float on the surface of the water. This form of flotation takes place to a greater or less ex- tent with most minerals, and is apparently a different phenomenon from the simple floating of particles by dropping them on the surface. In the latter case there is an almost continuous film of air surrounding the under side of the mineral, and by far the greater portion of it is projected above the surface of the wat- er. That this film is not continuous and that the particle is partly wetted, can be shown by floating some magnetite substance, as pyrrhotite, and attracting it with a magnet, when the surface of the water will be dragged up with the mineral. When the substance ig finally lifted out, water is carried up to the mag- net. In the former case, the particles will be seen to be almost entirely submerged, only a portion like a pin's point being above the surface, and, altho' a dis- tinet depression of the surface is caused, it is not so deep as in the other case", The following is a list of the minerals tried that would float im small quanti- ties when sprinkled on the surface of cold water; Azurite, Augite, Aragonite, Calcite, Cerussite, Dolomite, Malachite, Rhodochrosite, Allamite, Bronzite, Beryl, Con- narite, Diopside, Tremolite, Scapolite and a very little Obsidian. These floated in larger quantities: Magnesite, Garnet, Hornblend* Vesuvianite, and Zircon. Some quartz samples floated and sone would not. Glass would not float. After shaking the same minerals, in cold water, in a test tube, a small part of some again floated, of others very little or none floated. A small part of the following floated: Azurite, Augite, Vesuvianite; less calcite, dolomite, garnet, allamite, and very little or none of these floated, beryl, hornblend, cerussite, mag- nesite, tremolite, rhodochrosite, zimcon, scapolite, ob- sidian, aragonite,bronzite, and dfopside. IN HOT WATER. In hot water the behavior of minerals is differ- ent. Some of them floated in about the same quantities as in cold water, others in less quantities and still others in larger quantities. Azurite, augite, calcite, aragonite, bronzite, cerussite, connarite, dolomite, di- opside, garnet, hornblend§ tremolite, magnesite, mala- chite, zircon, vesuvisnite and gbsidian floated the same as in cold water. More beryl and allanite floated and less rhodochrosite and scapolite floated in the hot wat- er. After shaking in hot water, the following minerals floated in about the same amounts as when shaken in cold waters Augite, azurite, calcite, dolomite, allanite, cer- ussite, connarite, hornblend¢ absidian, tremolite, magnes- ite, malachite, rhodochrosite, scapolite, vesuvianite, and zircon. Aragonite and bronzite did not float after shaking in cold water but in hot water a small acount of float was noticed. More beryl, diopside, and garnet floated in hot water than in cold water. Reduced Pressure. Prom K. A. Mickle's paper. "Many substances when sunk in water will rise to the surface when the pressure above the sufface of the water is lowered. Among the substances tried the fol- lowing floated: All the metals in the form of foil, sul- fur, graphite, mica, and zinc-blend concenentrated values. Particles of galena, cerussite, sand and calcite came to the surface but sank again. When a mixture of particles of zine blend and river sand was put into a vacuum flask under water under reduced pressure, it was noticed that the zinc blend came up more persistently than the sand, which rose to the surface three or four times, dut would not do so again. Particles of minerals are caused to float by gas bubbles attached to them. In some cases these bubbles are..strongly attached to the minerals. On some minerals bubbles will form, but the minerals do not float, as quartz, garnet, gypsum, hematite, wolfram- ite, cassiterite and glass. Pieces of metal in the form of foil will float even after being repeatedly sunk. If the water is boiled free from air the metals will not float if the first bubbles to attach themselves are re- moved. A piece of copper foil, immersed in air free water, which would not float when the pressure was re- duced, floated on the surface when brought in contact with the vapor above the surface of the water. Crys- talline pieces of the following minerals, under water and with reduced pressure, were all coated with bubbles: galena, blend, garnet, tourmaline, pyrite, gypsum, anda- lusite, cgleite, cerussite and quartz. These minerals were then placed in water boiled free from air and again became coated with bubbles on reducing the pressure, thus a wn showing that some gas is carried down with each mineral as it sinks. The metals also had bubbles attached to them, but on freeing these with a glass rod only a few very minute ones formed again. After the bubbles have formed on these minerals, if atmospheric pressure is re- stored, the bubbles become almost invisible, but expand again in the same position on again lowering the pressure. Tarnished minerals form as many bubbles on their surfaces Nn a8 the clean ones. Dilute Acid Solution. In a cold dilute HpS0, acid solution, the minerals acted about the same as in cold water. None of the min- erals would float when sprinkled on the surface of hot acid solution, even when very dilute, but became at once wetted and sunk. Alkaline Solution. The minerals would float on the surface of dilute NaOH solution, but for a few seconds only, and then become wetted and sink. When heated in a solution of NaOH, the minerals will not float. 0il and Water Combinations. All the minerals absorbed oil and floated when shaken in water to which a few drops of paraffin oil were added. Some showed a marked selection of the 0il and floated in relatively large amounts, while oth- ers absorbed but little oil and floated in small amounts. In a hot solution the following minerals floated very well: Augite, azurite, allanite, beryl, and malachite. On tapping the tube the float slowly dropped back in small oil pellets, but would float again on being agitated. When left standing for a few minutes the mineral would fall back entangled in the oil. The following gave a poorer float: Aragonite, calcite, dolomite, bronzite, cerussite, diopside, garnet, magnesite, obsidian, vesu- vianite and zircon. The following gave no float: Con- narite, hornblendg tremolite, rhodoechrosite, and scapo- lite. In cold solutions at the temperature of tap wat- er, the behavior of the minerals was different. All of the minerals floated as well in the cold solutions as in the hot. Several gave a better float and some were more persistent in remaining afloat. Augite, aragonite, calcite, bronzite, beryl, connarite, diopside, garnet, hornblends, obsidian, tremolite, magnesite, malachite and scapolite acted the same in cold solution as in the hot. Azurite, allanite, dolomite, zircon, and vesuvianite, floated in larger amounts. The following: Azurite, cer- ussite and rhodochrosite gave a very persistent float, re- quiring sharp tapping on the tube before they dropped back in pellets of oil. Alkaline and Acid Solutions and Oil. When a small amount of Nap CO, is added to the com- bination, the oil and mineral with many small ges bubbles strongly adhere to the test tube as a coating around the inside surface. On adding a few drops of HyS0,4 the liberated CO, gas raises much of the mineral but it quick- ly drops back again. The mineral and oil leave the sur- face of the tube and on adding more acid the oil spparates from the mineral and floats, leaving the clean mineral be- hind, When the solution is heated after adding the acid the oil separates from the mineral more quickly. The quantity of float of many of the minerals was consider- ably increased by the addition of a small amount of NaOH to the oil and water combination. The oil and water solution became opaque when shaken together but in some cases is dleared again with the NaOH, which apparently causes the oil to collect in larger particles. This clearing was noticed in solutions containing the minerals tremolite, diopside, scapolite, zircon and obsidian. Mag- nesite, malachite, and rhodochrosite became semi-transpar- ent. The tremolite solution became more opaque when made slightly acid but with the other solutions the addition of acid cleared them. NaOH apparently causes a stronger ad- hesion between the mineral and oil and they tend to collect gas bubbles more regdily and float. Also the mineral, 0il and gas bubbles have a very strong adhesion for the glass tube, in alkaline solutions. A marked increase in the float of the following minerabks in NaOH solution was noted: Cerussite, connarite, dolomite, diopside, tremolite, magnesite, fhodochrosite, scapolite, vesuvianite, zircon, and obsidian. Very little increase is noticed in the amount of garnet, hornblendg, and malachite. Making the solution acid with a few drops of HpS0, caused less min- _ eral to float. The oil tended to leave the mineral and when more acid is added, the separation takes place more quickly. Heat is also an aid in separating the oil from the mineral in an acid solution. Some minerals cling more persistently to the oil than others, resisting the cleansing effect of the acid and heat. Cerussite, ocon- narite, dolomite, diopside, zircon, and rhodochrosite showed this tendency. If oiled rock minerals and a metallic sulfide as galdna are shaken in water and acid is added, the oil tends to leave the rock minerals and only the sulfide floats. Behavior of Rock Powders in Different Solutions. A piece of grano-diopite was crushed and tested in three sizes: Between 60-70 mesh, 70-80 mesh, and 80- 100 mesh and a number of different oils were used. In all cases the finer mesh powder absorbed the more oil and gave a poorer float than the coarser mesh. All of the mineral components of the orushed rock were found in the float, when shaken in water containing a few drops of oil but biotite was concentrated considerably in excess of the other minerals. With a few of the oils used biotite was concentrated to about 80 per cent of the float. This excess over the other minerals may be due to its flaky nature, which exposes a relatively large surface per vol- ume for the adhesion of the oil and gas bubbles. The behavior of the powder in different oils was noted. Some gave a relatively good float while others produced poor ones or none at all. Tusel oil, when shaken with the powdered rock in water, produced a collection of dirty scum which floated on the surface of the water. In Nag CO, and HpS0, solutions the results were the same. Clove cil in an alkaline solution floated everything in the powder with biotite concentrated to about 80 ver cent. In an acid or neutral solution a very poor float was pro- duced. Paraffine oil and Xylol each gave a good float which showed a distinct biotite concentration. On add- ing a little (NH4)oC00z; the float disappeared; the 0il min- eral and gas bubbles adhering to the glass test tube. On liberating COp gas with a few drops of HpS04 added to the solution much mineral is picked up and floated but soon drops back again. The acid causes the oil and mineral to leave the glass surface of the test tube and the oil slowly separates from the mineral and floats, Oleic acid, creosotes, pine and cotton seed oils each produce a poor float with no concentration of any minerals. Light pine 0il and oleic acid when shaken together in a warm solu- tion concentrate the biotite. Also cotton seed oil mix- ed with heavy pine oil gave a good biotite concentration over other minerals. In Sulfate Solutions With 0il. A grano dionite containing about equal amounts of biotite and muscovite was crushed and tested in the following sulfate solutions. A few drops of paraffin 0il in an ammonium sulfate solution floated principally muscavite with a slight concentration of biotite and chlorite. In an iron sulfate solution more float was produced and the muscovite and biotite about equally concentrated with a little chlorite. In copper sul- fate a cleaner float was produced with equal concentra- tion of the micas and some chlorite, over the other min- eralse. In sodium sulfate the muscovite was largely concentrated with little biotite and other minerals. Summary . Particles of minerals are not wholly wetted when sprinkled on the surface of water, or when immersed in it. They absorb gasses which tend to float them to the sur- face. Heat apparently affects this gas attachment to the mineral. Some minerals floated better in heated solutions than in cold ones. Metallic particles such as sulfides when immersed in dilute acid solutions are not wholly wetted, but particles of rock minerals become * , more readily wetted and give off their absorbed gases. 13 If sulfides and rock minerals are mixed and shaken with 0il in a dilute acid solution the sulfide only will float. This selective flotation is caused by the acid which re- moves the oil from the rock mineral but not from the sul- fide. In alkaline solutions the mineral particles send to part with their absorbed gases and will not float. If previously oiled a good Float is obtained in: a NaOH solu- tion;with rock powders selective flotation was limited principally to the micas altho a small chlorite concentra- tion was noted. In sulfate solutions with oil the amount of float produced was amall but a slight selective flota- tion was obtained. In sodium and ammonium sulfate solu- tions muscovite floated in excess of biotite while in iron and copper sulfate solutions muscovite and biotite floated equally -.:@ well, A small concentration of chlorite over the other minerals in the rock powder, was obtained in all of the sulfate solutions. Bibliography. Kenneth A. Mickle, Proceedings of the Royal Society of Vietoria, Vol. XXIII (NS) 2, March, 1911. Experiments on Crystalline fragments, etc. Prancis C. Nicholas, Mining World. Vol. XXVIII, pg. 18, 1908. Graphite washings, etc. Fritz Cirkel, Canada, Mines Branch. Ottawa. 1907, pg. 219, Description of U. S. Patent issued to E. B. Kirby for an oil flotation process for graph- ite. The Behrend Wet Flotation & Concentrating System. Canadian Mining Journal. Vol. XXX, pg. 279~- 80, 1909. Used for many minerals. T. J. Hoover, Concentrating Ores by Flotation. pp. 168-201. Bibliography. END OF TITLE