Bacteria Cellulose
A chemical has been created using an advanced biotechnological process involving a strain of bacteria that produces cellulose. The resulting product, called Cellulon, has properties that make it useful for thickening and binding applications in the mining industry, according to Weyerhauser Co., which developed the chemical.
Cellulon fibre has a novel physical structure compared with other forms of cellulose — an intricately crosslinked network of fine fibres rather than the distinct fibres of measurable length common to other forms. Because of this and the fibre’s thinness, it has 200 times more surface area than softwood pulp fibres. This, plus its hydrogen bonding capability, makes it useful in binding and thickening applications at very low concentrations.
Cetus Corp. of Emeryville, Calif., worked in concert with Washington state-based Weyerhaeuser to develop a strain of Acetobacter bacteria, which can be scaled up to large-volume commercial production. No other bacterial cellulose process can produce large quantities affordably, Weyerhaeuser reports. The problem has been that the cellulose-producing ability of Acetobacter strains is adversely affected by shear, but shear and agitation are necessary to transfer oxygen for cell growth in large fermentation tanks. To obtain a strain that could produce cellulose under shear during fermentation, Cetus scientists screened for strains that had a much lower frequency of reversion to non-cellulose producers under agitation.
Cellulon is advantageous in the following metal applications, according to Weyerhaeuser:
froth flotation talc depressant reagent;
mineral binder, including iron ore pelletizing and copper or gold heap leaching (Cellulon binder performs under both acid and alkaline conditions); and
ceramic or other metallic powders processing binder.
“Cellulon fibre, with its superior qualities, will help our customers in mining and metals produce higher-quality products,” says E.L. Soule, vice-president of research and engineering at Weyerhaeuser.
Loading Spouts
Six XP-8 retractable, dust-free loading spouts are now available from the Superior Systems division of W.W. Sly Manufacturing Co. Each delivers up to 200 cubic ft. per minute and is used to load trucks and rail cars with calcium carbonate.
EZ View, as the spout design is called, allows visual control of the loading operation through built-in viewing ports. Operators can watch the product loading to avert spillage. External shrouding, internal telescopic product guide cones and a specially controlled air stream remove fugitive dust.
Economical Micro PLC
A miniature, low-end programmable controller has been introduced by Modicon Inc. of Montana. Designed for use with Modicon’s compact 300 Series I/O products, the Micro-984 is used in new applications in which space is limited and as a logical retrofit product for existing Micro-84 installations.
The controller comes equipped with 4 K of user logic and 2 K of register space for a total of 6 K words. It includes the standard 984 family instruction set.
Outokumpu Aerators
Model oki aerators, featuring the highest oxygen transfer rate of any waste water treatment aerators, are now available from Outokumpu Equipment Canada. The high oxygen transfer rate means fewer units are required per installation, compared with other aerators on the market, according to an Outokumpu press release. Also, costs for installation, power and maintenance are all said to be reduced.
The free-standing configuration and weighted base of oki aerators eliminate the need for costly pontoons, bridges, special footings or other support structures. And piping requirements are significantly reduced thanks to a flexible hose connected to the high-capacity air intake.
A unique combination impeller provides both aeration and mixing, increasing the efficiency of waste water, reports Outokumpu. The unit’s non-clogging and non-fouling design eliminates the need for cleaning, even with the most difficult waste waters. The motor housing is continuously purged of air to ensure long motor life.
In addition to having the highest oxygen transfer rate available, oki aerators are able to control this rate to correspond to the treatment system’s biological oxygen demand. Denitrification of the treatment system is simple because of the aerator’s ability to control aeration and mixing independently. To achieve denitrification, mixing is maintained while the air supply is turned off.
Level Measurement System
Milltronics Process Measurements of Peterborough, Ont. has introduced an ultrasonic system for measuring volume or level in one to 10 vessels. AiRanger xpl, as the system is called, monitors both bulk solids and liquids in ranges up to 61 metres.
The core of the system is an ultrasonic technique which achieves precise level measurements and which can be adapted to variations in any vessel.
The system consists of a compact display unit with removable programmer which can be situated conveniently on the bin floor, as well as any of Milltronics lr or st series transducer.
Wiring costs and installation time are both low, says a release from Milltronics, because the alarm and analog output modules can be situated where needed and linked to the main desplay with a single 2-conductor cable.
Altered Analyzer
Introduced two years ago, the gradex particle size analyzer now had additional features for loading and for collection, storage and retrieval of data. This reduces the device’s manpower requirements for sieve analysis.
The operator can now load, identify and select the desired analysis for up to six separate samples at one time. Once the cycle for the first sample is initiated, the unit automatically analyzes each of the six samples as they are sequentially fed. It also calculates and stores weight values and produces a computer printout by weight for each fraction — thus freeing the operator to perform other tasks.
A new personal computer-based control system presents and evaluates analysis data. Upon completion of the analysis, the data are displayed on the color monitor in bar chart or tabular format, which can be printed on the dot matrix printer.
Based on 50 samples per day, Gradex saves enough manpower to pay for itself in just 12 months, according to literature available from Rotex Inc. of Cincinatti, Ohio, which manufactures the analyzer.
Wear-resistant Material
A wear-resistant material for hydrocyclone linings, apexes and other components in high-wear situations is now available from Alanx Products of Newark, Del. The material, called ALANX CG896, is a ceramic/metal composite and it is rapidly displacing other wear materials such as ceramics, the manufacturer reports.
The new, dense material consists of silicon carbide particles bound together by a matrix grown by the oxidation of molten metal. Besides being stronger than ceramics, ALANX CG896 is said to be 10 to 20 times more wear-resistant than metal.
Vacuum Contactors
A new line of vacuum contactors, suitable for use in dusty, hostile environments, is available from Saftronics Inc. of Ft. Myers, Fa. Their compact size makes them well-suited for new as well as retrofit applications, Clear glass vacuum bottles instantly show the condition of the vacuum by a change in color in the unlikely event of a leakage, providing early warning of switching problems. The bottles can withstand high surge currents, while keeping chopping currents at low levels. Coil voltage is 120 VAC.
Be the first to comment on "METALLURGICAL GRAB-BAG"