Mixtures solid

When used to separate solid-solid mixtures, the material is ground to a particle size small enough to liberate particles of the chemical species to be recovered. The mixture of solid particles is then dispersed in the flotation medium, which is usually water. Gas bubbles become attached to the solid particles, thereby allowing them to float to the surface of the liquid. The solid partices are collected from the surface by an overflow weir or mechanical scraper. The separation of the solid particles depends on the different species having different surface properties such that one species is preferentially attached to the bubbles. A number of chemicals are added to the flotation medium to meet the various requirements of the flotation process ... 

One application of the grand canonical Monte Carlo simulation method is in the study ol adsorption and transport of fluids through porous solids. Mixtures of gases or liquids ca separated by the selective adsorption of one component in an appropriate porous mate The efficacy of the separation depends to a large extent upon the ability of the materit adsorb one component in the mixture much more strongly than the other component, separation may be performed over a range of temperatures and so it is useful to be to predict the adsorption isotherms of the mixtures. 

The process of extraction with solvents is generally employed either for the isolation of dissolved substances from solutions or from solid mixtures or for the removal of undesired soluble impurities from mixtures. The latter process is usually termed washing. 

Acidify the aqueous solution (60-76 ml.)= prepared from (a) 6-10 g. of the solid mixture, ( >) from 6-10 g. of the liquid residue (fJ) after distillation from a boiling water bath, or (c) from sufHcient of original aqueous solution to contain 6-10 g. of solute) with 20% E fSOf and distil. 

Gas-Solid Mixtures Carlson, Frazier, and Engdahl [Trans. Am. Soc. Mech. Eng., 70, 65-79 (1948)] describe the use of a flow nozzle and a square-edged orifice in series for the measurement of both the gas rate and the solids rate in the flow of a finely divided solid-in-gas mixture. The nozzle differential is sensitive to the flow of both phases, whereas the orifice differential is not influenced by the sohds flow. 

Farbar [Trans. Am. Soc. Mech. Eng., 75,943-951 (1953)] describes how a venturi meter can be used to measure solids flow rate in a gas-solids mixture when the gas rate is held constant. Separate calibration curves (solids flowversus differential) are required for each gas rate of interest. 

Cheng, Tung, and Soo [J. Eng. Power, 92, 135-149 (1970)] describe the use of an electrostatic probe for measurement of solids flow in a gas-solids mixture. 

Liquid-Solid Mixtures Liptak [Chem. Eng., 74(4), 151-158 (1967)] discusses a variety of techniques that can be used for the measurement of sohds-in-liquid suspensions or slurries. These include metering pumps, weigh tanks, magnetic flowmeter, ultrasonic flowmeter, gyroscope flowmeter, etc. 

Filtration is the separation of a fluid-solids mixture involving passage of most of the fluidthrough a porous barrier which retains most of the solid particulates contained in the mixture. This subsec tion deals only with the filtration of solids from liquids gas filtration is treated in Sec. 17. Filtration is the term for the unit operation. A filter is a piece of unit-operations equipment by which filtration is performed. The filter medium or septum is the barrier that lets the liquid pass while retaining most of the solids it may be a screen, cloth, paper, or bed of solids. The hquid that passes through the filter medium is called the filtrate. 

Regardless of the method of evaluating the solids mixture, the sampling procedure is vital. Often a sampling thief, or other special device, is used to remove samples from the mixture without excessive disturbance of the batch. If an easier method of sampling is obvious and will bring less contamination to the batch, it should be used. 

A standard testing procedure for solids-mixing equipment is available (Ref. 1). This contains details and references pertaining to sampling from solids mixtures for both batch and continuous mixing. 

The term du.st is used if the maximum particle size of the solids mixture is below 500 [Lm. 

A. Extraction with Benzene.—The mandelic acid is separated from the ammonium chloride by extraction with hot benzene. This is best done by dividing the solid mixture into ten approximately equal parts (Note 7). One of these portions is placed in flask with i 1. of boiling benzene. After a few minutes the hot benzene solution is decanted through a suction funnel (Note 8). The filtrate is cooled in an ice bath and the mandelic acid that crystallizes is filtered with suction. The benzene is returned to the extraction flask containing the residue from the first extraction, and a new portion of the ammonium chloride-mandelic acid mixture is added and extracted as before. The process is repeated until the mandelic acid is completely removed from the ammonium chloride (Note 9). 

B. Extraction with Ether (Note 10).—The solid mixture is transferred to a 2-1. flask and shaken ten minutes with 750 cc. of ether. The ether solution is decanted through a suction filter and the solid thrown onto the filter and pressed dry. The solid is then returned to the flask and shaken with 400 cc. of ether, d his mixture is filtered by suction and the solid washed twice on the filter with 250 cc. portions of ether. Each portion is allowed to drain through the filter several times while the solid is kept... 

Saturated hydrocarbons such as neopentane, notbomane, and cyclooctane have been converted to the corresponding perfluoro derivatives in 10-20% yield by gas-phase reaction with fluorine gas diluted with helium at —78°C. Simple ethers can be completely fluorinated under similar conditions. Crown polyethers can be fluorinated by passing an Fa/He stream over a solid mixture of sodium fluoride and the crown ether. Liquid-phase fluorination of hydrocarbons has also been observed, but the reaction is believed to be ionic, rather than radical, in character. A variety of milder fluorination agents have been developed for synthetic purposes and will be discussed in Chapter 6 of Part B. 

Dissolved Solids Boiling Pt/Freezing Point For Liquids/Solid Mixtures Bulk Density Total Solids Content Solids Size Distribution Suspended Solids Content Suspended Solids Settling Rate Dissolved Solids Content Free Water Content Oil and Grease Content Viscosity For Gases Density... 

Leaching, which is the selective solution of specific constituents of a solid mixture when brought in contact with a liquid solvent. It is particularly useful in separating metals from solid matrices and sludge. 

Removal by Gravitational Force. This method simply involves a settling chamber in which the fact that the liquid-solid mixture-solid pore interface has little holding power. Thus, given sufficient time, the solids will settle into the base of the chamber due to gravitational forces. 

Gaseous hydrogen chloride is bubbled through a solution of 0.8 g of 22,23-dibromoergost-8(14)-en-3/3-yl acetate in 25 ml of chloroform at 0° for 2 hr. The solvent is removed by evaporation and the solid mixture of A8(i4) A -isomers is hydrogenated over platinum oxide (0-2 g) in ether... 

Selective hydroxylation with osmium tetroxide (one equivalent in ether-pyridine at 0 ) converts (27) to a solid mixture of stereoisomeric diols (28a) which can be converted to the corresponding secondary monotoluene-sulfonate (28b) by treatment with /7-toluenesulfonyl chloride in methylene dichloride-pyridine and then by pinacol rearrangement in tetrahydrofuran-lithium perchlorate -calcium carbonate into the unconjugated cyclohepte-none (29) in 41-48 % over-all yield from (27). Mild acid-catalyzed hydrolysis of the ketal-ketone (29) removes the ketal more drastic conditions by heating at 100° in 2 hydrochloric acid for 24 hr gives the conjugated diketone (30). 

The dry gas has been made by direct reduction of a solid mixture of nitrite and nitrate with chromium(III) oxide (3KNO2 4- KNO3 4-Cr203 —4NO 4- 2K2Cr04) but is now more conveniently obtained from a cylinder. 

A mixture of 26.1 g of o-benzylphenoxy- J-chloropropane and 17 g of pipiridine Is refluxed over a period of 32 hours until the temperature is about 124t and a nearly solid mixture is formed due to the precipitation of a salt. The mixture is then refluxed over a period of 48 hours at about 160 3 and the reaction product obtained is cooled and dissolved in methanol. The solution is concentrated under reduced pressure to yield an oil which is added to 200 ml 3N hydrochloric acid whereupon the mixture is shaken with ether, 3 x 100 ml, until the aqueous phase Is clear. The ether solution is washed with water, 3 x 50 ml, and the water present in the combined aqueous phase and water used for washing Is evaporated under reduced pressure methanol being added three times when the residue appears to be dry. The impure hydrochloride of o-benzylphenoxy- J-N-piperidinopropane, 41 g, obtained is dissolved in 100 ml water and 100 ml 30% aqueous sodium hydroxide solution are added, whereupon precipitated oil is extracted with ether, 1 x 100 and 2 x 50 ml. The ether solution is washed with water, 4 x 50 ml, dried with magnesium sulfate and the ether is removed under reduced pressure. The residue, 252 g, is distilled under reduced pressure and the main fraction,... 

Click Coached Problems for a self-study a dissolved species or its percentage in a solid mixture. This is done by carrying out a titra-... 

Conversion of carbon to carbon monoxide. In the lower part of the furnace, coke burns to form carbon dioxide, C02. As the C02 rises through the solid mixture, it reacts further with the coke to form carbon monoxide, CO. The overall reaction is... 

It is important to note that the one-step conversion of 27 to 28 (Scheme 4) not only facilitates purification, but also allows differentiation of the two carbonyl groups. After hydrogenolysis of the iV-benzyl group (see 28—>29), solvolysis of the -lactone-ring in 29 with benzyl alcohol and a catalytic amount of acetic acid at 70 °C provides a 3 1 equilibrium mixture of acyclic ester 30 and starting lactone 29. Compound 30 can be obtained in pure form simply by washing the solid mixture with isopropanol the material in the filtrate can be resubjected to the solvolysis reaction. 

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