DECEMBER 1956
I/EC Briefs The
why,
what,
and
articles in this issue. reference a n d easy
significance
of
technical
Clip these Briefs for ready filing
on a 3 X 5 or other
suitable card
Ind. Eng. Chem. 48, 2107 (1956)
Recovery of Cyanide from Waste Cyanide Solutions by Ion Exchange
STAFF-INDUSTRY COLLABORATIVE REPORT
Recovery of cyanide from the adsorption of simple and complex ions from gold barren waste or waste cyanide solutions has b e e n possible by the use of strong IRA-400 ion exchange. T h e process was developed to employ the alkaline waste solution and a limited source of available economical reagents—sulfuric acid, sodium chloride, and sodium carbonate. In the sorption cycle, two or more glass columns were used and the flow rate was maintained at 0.27 b e d volume per minute. Adsorption of the cyanide ions on cuprous cyanide showed consistent results. ERIC GOLDBLATT Stllfontein Gold Mining Co., Ltd., Transvaal, Union of South Africa
Ind. Eng. Chem. 48, 2095 (1956)
Gold Processing T h e Union of South Africa produces approximately half of the world's production of gold. Daggafontein Mines Ltd., largest of Anglo American group, operates two gold plants which last year processed 2,600,000 tons of ore from which was recovered 607,430 fine ounces of gold. T h e solubility of gold in cyanide solution plays a key role in its recovery from finely milled ore. Important stage i n processing takes place i n air agitated Pachuca tanks, where gold and silver are dissolved in weak cyanide solution. Large rotary filters separate the gold bearing liquor from the remaining slime, and zinc dust is employed to precipitate the precious metals as well as copper, zinc, and lead present. After b e i n g calcined and smelted at reduction plant, gold is further purified at a central laboratory. In recent years, hydrocyclones h a v e replaced the conventional mechanical classifiers in gold milling circuits. Red u c e d labor and maintenance costs are resulting in widespread substitution of cyclones for less efficient and more costly classifiers.
Ind. Eng. Chem. 48, 2115 (1956)
Batch versus Continuous Processing in Fluidized Nuclear Reactors T h e effect of batch and continuous processing upon formation of transmutation products and their associated neutron losses have b e e n examined for fluidized reactors. It is concluded that for equal processing periods, a smaller content of higher order by-products (or contaminants) and lower neutron losses will result u n d e r many conditions of interest in batch compared to continuously processed reactors. This advantage increases markedly as the order of formation of the by-product increases. In particular, uranium-232 and -234 impurities in uranium-233 produced in a thorium blanket a n d losses due to fission products produced in a core were examined. J. HALPERIN and R. W. STOUGHTON Oak Ridge National Laboratory, Oak Ridge, Tenn.
W I L L I A M Q. HULL and CECIL STENT
VOL. 48, NO. 12
·
DECEMBER 1956
Ç] A
BRIEFS Clip these Briefs for ready reference and easy filing on a 3 X 5 or other suitable card
Ind. Eng. Chem. 48, 2123 (1956)
Poly-α-methylstyrene Because of the availability of α-methylstyrene and an economical method of polymerization (sodium catalysis), it was desired to evaluate the properties of poly-a-methylstyrene, a thermoplastic which can be subjected to tempera tures as high as 125° C. without distortion. If breakdown and strain during fabrication are avoided, the plastic is re sistant to temperatures 10° to 25° C. higher. Exposure to these temperatures for long periods (months) causes embrittlement. Poly-a-methylstyrene is normally more brittle than poly styrene and a low molecular weight and narrow distribution is desirable in order to combine useful physical properties with optimum moldability. Injection molding requires high pressure and good temperature control in order to minimize depolymerization. Hardness and solvent re sistance are other properties of interest.
RE-USE OF WATER BY INDUSTRY
G. D. JONES, R. E. F R I E D R I C H , T. Ε. WERKEMA, and R. L. Z I M M E R M A N Dow Chemical Co., Midland, Mich.
Ind. Eng. Chem. 49, 2132 (1956)
Ind. Eng. Ch = m. 48, 214S (1 )36)
Ionic Derivatives of Polyacrylamide
Re-use of Steam Condensate as Boiler Feedwater
Ionic derivatives were prepared from polyacrylamide through its chemically reactive amide groups in order to enlarge the scope of its possible uses. Three types of prod ucts are described: Anionic derivatives via sulfomethylation with formaldehyde and sodium bisulfite; cationic de rivatives via the Hofmann degradation reaction with alkali and hypohalite; and cationic derivatives via aminomethylation or Mannich reaction with formaldehyde and amines. The ionic products prepared were evaluated as wet strength resins for paper, soil conditioners, drilling-mud additives, and in other uses that require an ionic, watersoluble polymer.
Because modern boilers require feedwater of high purity, power plant operators generally find that it pays to re-use condensed steam. However, they must face problems re sulting from corrosion and contamination. Ravages of condensate corrosion may be combated and losses caused by deposits lessened by modifying treatment of the make-up, feedwater or boiler water, by making me chanical changes to reduce the concentration of corrosive substances in the steam condensate, and by conditioning the steam with materials that inhibit attack by corrosive condensate.
A. M . SCHILLER and T. J . SUEN American Cyanamid Co., Stamford, Conn.
D. E. NOLL and Η. Μ. RIVERS Hall Laboratories, Inc., Pittsburgh, Pa.
Ind. Eng. Chem. 48, 2151 (1956) Ind. Eng. Chem. 48, 2138 (1956)
Carboxylic Rubbers from Scrap Vulcanized Rubber Unsaturated acids react with vulcanized rubber during reclaiming to form carboxylated elastomers possessing unique properties, which depend upon the scrap and the amount of unsaturated acid used to make the carboxylated rubber. These include higher oil resistance, higher mod ulus, improved aging, and lower benzene extract. The different grades also possess properties that may be considered advantageous for special applications: high hardness relative to the rubbery hydrocarbon, and high hysteresis loss. The new polymer responds to curing mechanisms similar to those used for neoprene. The response to sulfur cure is diminished as the amount of maleic anhydride is increased. JOSEPH GREEN and E. F. SVERDRUP U S. Rubber Reclaiming Co., Inc., Buffalo, Ν. Υ.
Conservation of Water in the Pulp and Paper Industry Although all types of normal water classifications are re quired in the manufacture of pulp and paper, process waters are in greatest demand. Recycle and re-use are furthest de veloped in pulp washing, screening, bleaching, and papermaking. Improvements in process methods and equipment are stimulated by tightening availability of water and em phasis on pollution abatement. Limiting factors in the re cycle of process water are adverse effects on the individual operating departments and the end product. Conservation practices in the individual mill, dictated by the specific situation and fostered by necessity, involve further integration of water usage. Re-use of process water continues to increase in the face of ever-increasing produc tion. HOWARD B. BROWN National Council for Stream Improvement, Inc. Louisiana State University Baton Rouge, La.
VOL. 48, NO. 12
·
DECEMBER 1956
93 A
BRIEFS
Clip these Briefs for ready reference and easy filing on a 3 X 5 or other suitable card
Ind. Eng. Chem. 48, 2168 (1956) I n d . Eng. Chem. 48, 2156 (1956)
Recirculation of Cooling Water in Petroleum Refining Use of untreated or improperly treated cooling water causes many problems in the refining of petroleum— corrosion, scale deposition, biological fouling, and cooling tower deterioration. Fifteen years of experimentation at the EI Segundo Re finery of the Standard Oil Co. of California have developed chemical treating procedures and methods of controlling water concentration to prevent or alleviate these difficulties. A. J . BRANDEL California Research Corp., El Segundo, Calif.
Adaptation of Treated Sewage for Industrial Use Among the methods for meeting the growing d e m a n d for water in industry, the conservation and re-use of sanitary and industrial wastes are recognized as a practical solution to many water problems. T h e treatment of liquid wastes for further use has passed the experimental stage. Methods are available which will restore most waste waters to the quality required for many purposes. These methods are now producing fairly large quantities of usable water both in this country and abroad. There are problems involved in the re-use of sewage, but in most cases these can be overcome. SHEPPARD T. POWELL 330 North Charles St., Baltimore, M d .
Ind. Eng. C h e m . 48, 2159 (1956)
Re-use of Cooling Water in an Atomic Energy Commission Installation In «rater-cooled atomic reactors total solids content of less than 0.5 p.p.m. is often required, to hold to a minimum the development of radioactivity within the primary coolant stream as it flows through the reactor core. This purity is obtained b y ion exchange (demineralization). Ion exchange resins are also used as a bypass cleanup unit in the primary coolant water loop to remove built-up radioactivity. These resins become highly radio active and are usually b u r i e d . Regeneration is possible, but disposal is generally cheaper. Holding t h e primary coolant water stream at an acceptable radioactive level is costly, but use of bypass cleanup units to eliminate the n e e d for continuous purge permits a con siderable saving. Secondary coolant systems are still necessary for dissipation of generated heat.
IMPROVEMENTS IN FERMENTATION EQUIPMENT AND DESIGN
A. L. BILADEAU Atomic Energy Commission, Idaho Fails, Idaho
Ind. Eng. C h e m . 48, 2172 (1956) Ind. Eng. Chem. 48, 2162 (1956)
Biological Fouling in Recirculatiug Cooling Water Systems Slime and algae are common problems of recirculating cooling water systems. Deposits of biological origin can interfere seriously with heat transfer. Among the control agents used are chlorine, bromine, chlorinated phenols, copper salts, and quaternary ammo nium compounds. Selection of the proper toxicant involves consideration of many factors. Fungus attack of cooling tower wood is a related problem. JOHN J . M A G U I R E W. H. & L. D. Betz, Philadelphia, Pa.
Fibrous Filters for Air Sterilization Design Procedure Fibrous filters for air sterilization may be designed on a rational basis from the results of laboratory tests. Informa tion is required on expected loading, desired filter life, and the penetration-velocity relationship for the filter material in use. A series of filters of different b e d depths and volumes may b e specified for a given j o b . T h e n pressure drops are evaluated and the optimum filter is selected. T h e characteristics of the filter b e d and holder are far more important to successful filter operation than depth. ELMER L. GADEN, Jr., and A R T H U R E. HUMPHREY Columbia University, New York 27, Ν. Υ.
VOL.
4 8 , NO. 12
·
DECEMBER 1956
95 A
BRIEFS Clip these Briefs for ready reference and ea
filing on α 3 X 5 or other suitable card
Ind. Eng. Chem. 48, 2190 (1956)
Equipment for Small Scale Fermentations Ind. Eng. Chem. 48, 2177 (1956)
Fibrous Filters for Air Sterilization Experimental Studies with a Pilot Scale Filter A fibrous b e d filter supplying air for fermentation proc esses was tested on a pilot plant scale, in order to check the design method a n d data o n filter efficiency provided b y a laboratory investigation. Correlation with laboratory data is good, although such factors as high entrance velocity a n d the true depth of the packed b e d were not considered. W I L L I A M D. MAXON and ELMER L. GADEN, Jr. Upjohn Co., Kalamazoo, Mich., and Columbia University, New York, Ν. Υ.
In fermentation, as in most other chemical processes, small scale equipment is advantageous for process develop ment. Information obtained, o n the basis of the same total cost for labor, equipment, raw materials, or physical space, is inversely proportional to tank size. H o w e v e r , percentage volume loss due to sampling and evaporation may b e appreciable, and there may be special sterility problems. In the 10-gallon stainless steel fermentors described process piping was of all-welded construction and all lines entered the head of the fermentor (except cooling water to the jacket), so that tank shells could be lowered for easy cleaning. Auxiliary equipment included an apparatus for humidifying process air, an electrical probe-relay-pump system for foam control, a n d a sterile metering system for handling slurries. In the same equipment, modified slightly, sterility of continuous fermentations was maintained for 2 months. C. L. KROLL, STANLEY FORMANEK, A. S. COVERT, L. A. CUTTER, J. M. WEST, and W. E. BROWN Squibb Institute for Medical Research, New Brunswick, N. J.
Ind. Eng. Chem. 48, 2180 (1956)
Fermentor Design for Small Scale Submerged Fermentations A 30-liter unit, designed for s u b m e r g e d fermentation re search, consists of three basic parts: a h e a d or top to which the internal a n d external accessories are mounted, a fermen tation vessel, a n d a frame to hold the vessel and h e a d to gether. T h e unique features of the design are the seal around the impeller shaft and the removable impeller shaft bearing unit. T h e fermentors are assembled and charged as individual units, and sterilized in a large horizontal autoclave. After sterilization, the fermentors are placed in water baths for temperature control and connected to a source of air and agitation. Sulfite oxidation values of 0.5 to 4.25 millimoles of o x y g e n per liter per minute are possible u n d e r the normal range of operating conditions of the fermentor.
Ind. Eng. Chem., 48, 2194 (1966)
Role of Turbine Impellers in Aeration of Activated Sludge Biological oxidation of wastes d e p e n d s u p o n supply of a sufficient quantity a n d concentration of oxygen to the solid organisms s u s p e n d e d in the liquid. This is essentially the gas-liquid mass transfer mechanism that exists in all fer mentation systems. Measurement of the effect of mixing variables on the aeration of activated sludge forms the basis of effective combination of air flow, mixer horsepower, and tank shape for a given process. T h e final decision for a given fermentation must be d e cided in the light of the economics involved. J. Y. OLDSHUE Mixing Equipment Co., Inc., Rochester, Ν. Υ.
WALDO C. FRIEDLAND, M E R L I N H. PETERSON, and JOHN C. SYLVESTER Abbott Laboratories, North Chicago, III. Ind. Eng. Chem. 48, 2183 (1956)
Equipment for Detailed Fermentation Studies Adequate study of most fermentation problems requires careful control of i n d e p e n d e n t variables and scrupulous examination of d e p e n d e n t variables. A fermentor a n d auxiliary equipment were designed. T h e stainless steel fermentor has a 20-liter operating capacity. Variable-speed agitator, air sparger, a n d all other interior facilities are connected through the h e a d , permanently mounted on a frame. T h e b o d y is removable for cleaning and loading and for modification of the internal components. An improved antifoam system is used. A small-holdup sample line and an air humidifier reduce volume losses to a minimum. A spring-loaded torsion dynamometer and tachometer provide for power measure ments. Internal steam-sterilizable electrodes are used for p H measurement and control. Carbon dioxide and oxygen in the vent gases are determined b y continuously recording instruments. Two-liter sparged and agitated seed vessels provide inoculum for the fermentor.
Ind. Eng. Chem. 48, 2199 (1956)
Testing of Filters for Phage Removal Apparatus and procedures suitable for the testing of bac teriophage removal b y fibrous filters are described. T h e technique employs a homogeneous aerosol of " n a k e d " coliphage T-2r, which is prepared b y atomizing purified virus suspensions into a dry air stream. T h e phage particles are tagged with radioactive phosphorus, which serves as a tracer and eliminates the n e e d for main taining viability of the virus. Penetration data for various filter mat porosities and gas flow rates were determined, and individual fiber efficiencies were correlated with the fraction fibers in the mats and the Reynolds n u m b e r describing flow conditions. T h e experi mental results compare well with those predicted from theo retical considerations. H. L. SADOFF and J . W. A L M L O F University of Illinois, Urbana, I I I .
H. A. NELSON, W. D. M A X O N , and T. H. ELFERDINK Upjohn Co., Kalamazoo, Mich.
VOL. 48, NO. 12
·
DECEMBER 1956
97
A
BRIEFS
Clip these Briefs for r e a d y reference and easy filing o n a
3 X 5 or other suitable card
Ind. Ind.
Eng. Chcm. 48, 2204 (1956)
Control of Oxygen Uptake in Deep Tank Fermentations An apparatus is described with which o x y g e n utilization may be controlled automatically to follow a predetermined program—a line drawn with a conductive paint on the re cording chart where the rate of o x y g e n utilization b y a fermentation is recorded. T h u s , the preparation of the program is very simple and flexible. T h e performance of the c o n t r o l system was tested with a bacterial and a fungal fermentation. T h e apparatus offers a direct and simple means for transferring aeration data b e t w e e n different fermentors. Its principle is based on the analysis and control of oxygen concentration of the effluent gas. Its application is therefore not limited by the geometry and size of the fermentor. PING SHU National Research Council Saskatoon, Saskatchewan, Canada
Eng. C h e m . 48, 2218 (1956
Temperature Gradients in Turbulent Gas Streams K n o w l e d g e of e d d y conductivity as a function of position and conditions of flow is helpful in predicting temperature distribution in turbulently flowing streams. T h e e d d y conductivity for air in a steady, nearly uniform stream flowing b e t w e e n parallel plates was measured for Reynolds numbers b e t w e e n 6000 and 56,000 at average temperature gradients from 167° F. to slightly over 660° F. per foot, as a function of position in the central portion of the channel. T h e e d d y Prandtl numbers were calculated from e d d y conductivities and e d d y viscosities found earlier. T h e results indicate a marked increase in the e d d y con ductivity with Reynolds number for a fixed position. T h e maximum value is found approximately one third of the way from each wall, with a small minimum value near the axis of flow. Any trend of the e d d y Prandtl n u m b e r to approach unity with increasing Reynolds number, below 56,000, was obscured b y uncertainties in predicting values of the e d d y viscosity for the conditions of flow encountered. N. T. HSU, K A Z U H I K O SATO, and Β. Η. SAGE California I n s t i t u t e of Technology, Pasadena, California
Ind.
Ind.
Eng. C h e m . 48, 2209 (1956)
Eng. C h e m . 48, 2224 (1956)
Sulfite Oxidation as a Measure of Aeration Effectiveness
Visible Emission Spectra of Two-Stage Flames of Diethyl Ether Produced in Flat-Flame Burner
T h e absorption of o x y g e n in copper-catalyzed sulfite solutions has b e e n widely employed to measure effective ness of gas dispersion and of aeration in fermentation equip ment. Considerable disagreement as to the nature of the controlling rate process has b e e n evident. T h e effects of gas a n d liquid velocities with constant interfacial area were examined in a special apparatus. Absorp tion rate was i n d e p e n d e n t of gas velocity; it remained fairly constant at lower liquid speeds, dropping off at h i g h e r values. It is concluded that the absorption rate is "liquidphase-controlled" but not in the ordinary sense. Results are best interpreted i n terms of the chemical reaction be tween sulfite and o x y g e n in solution. T h e sulfite method is adequate for comparing aeration effectiveness in various pieces of equipment b u t not a model for all aerobic fermentations.
Low-temperature combustion reactions, such as those giving rise to cool flames, are at the root of many practical engineering problems. Solutions to these problems d e p e n d on an understanding of the fundamental reaction kinetics. To contribute to this understanding spectroscopic studies were made of two-stage flames formed in a flat-flame burner with varying ether-air ratios. T h e visible (2900 to 7000 A.) cool flame spectra at all fuel-air ratios consisted of formalde h y d e bands and some unidentified radiation at longer wave lengths. T h e richest second-stage flames showed only form aldehyde bands, but as the flame was made leaner, these were gradually replaced by an intense spectrum of HCO and CH. This spectrum change is believed to be significant in the transition from cool to normal flame reaction and may help explain the kinetics of this critical process.
JEROME S. SCHULTZ and ELMER L. GADEN, Jr. Columbia University, New York 27, Ν. Υ .
Ind.
W I L L I A M G. AGNEW and JOHN T . AGNEW Research Laboratories Division, General Motors C o r p . , Detroit 2, M i c h .
Eng. C h e m . 48, 2213 (1956)
Effect of Physical Variables on Microbiological Transformation of Steroids T h e relationships b e t w e e n agitation-aeration and growth or product yield in antibiotic or other industrial fermenta tions hav e b e e n examined by many investigators. Recently, the microbiological transformation of steroids o p e n e d a n e w field in industrial fermentations. By using Aspergillus ochraceus to convert 4-pregnene-3,20dione to 4-pregnene-lla-ol-3,20-dione and 4-pregnene17a,21-diol-3,20-dione to 4-pregnene-lla,17a,21-triol-3,20dione, it was shown that the rate of hydroxylation is greatly dependent on mechanical agitation and air flow. A semicontinuous addition of steroid is preferable to a one-shot addition, as it permits high steroid concentrations, prevents secondary transformations, and provides for more accurate timing in terminating the reaction. EDWARD O. KAROW and DEMETRE Ν. PETSIAVAS Merck, Sharp &. Dohme Research Laboratories, Rahway, N. J .
Ind.
Eng. Chem. 48, 22321(1956 )
Hydrocarbon Composition and Viscosity-Gravity Constant of Rubber Processing Oils A simple system is used for classifying rubber processing oils of similar composition on t h e basis of viscosity-gravity constant and viscosity. T w o types of analyses, molecular and carbon, are used to determine the composition. From a prepared graph, carbon-type composition can be read directly if the viscosity-gravity constant and refractivity intercept are known. Only viscosity, gravity, and refractive index are n e e d e d to determine carbon-type composition. Data are presented for commercial rubber processing oils from various locations analyzed b y the carbon-type com position procedure. S. S. KURTZ, Jr., R. W. K I N G , and J . S. SWEELY Sun Oil Co., Marcus Hook, Pa.
VOL.
48, N O . 12
·
DECEMBER 1956
99 A
