RECLAIMING

However, it is believed that incineration of strap tires is not the most desirable long-run approach when the total natural resource situation is considered. Scrap tires, a discarded resource rich in hydrocarbons, should be returned to the production cycle as useful materials, such as reclaim, reinforcing carbon black, and carbon compounds that could be chemical feed stocks. This last approach would conserve gas and oil reserves. 

Up to the time of World War 11, scrap tires contained only natural rubber. Reclaiming processes were well established, and a reasonable proportion (20%) of reclaim was accepted in compounding of new tires. (Frequently, the percentage was much more in other rubber products.) In 1941 the consumption of reclaim was 32% of the consumption of new rubber. 

The significant reclaim processes in use in 1974 were the digester process, heater process, and mechanical processes [3], But there were at that time numerous variations and combinations of these. All have similar finishing steps. The reclaim is usually further compounded, refined on tight mills, and strained to remove foreign solids. 

The reclaiming industry in 1974 was in an era of decline that started about 1960. Total production of reclaim, usage of installed reclaiming capacity, and proportion reclaimed of the available scrap all fell during this period. 

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Can you believe that A chemist just recreated a wondrously complex substance that, before now, was only a gift from God to man via plants. Man took this gift away from her fellow man but now, through the unbelievable power of chemistry, man can reclaim her right to self determination. Albeit illegally of course. 

Oil-free alkyds Oil from seeds Oil-in-water emulsion Oil laundering Oil length Oil mining Oil of anise Oil of bergamot Oil of eucalyptus Oil oflemon Oil of Olay Oil of Palma Christi Oil of turpentine Oil Orange Oil-pump Oil reclaiming Oil recovery... 

Demilitarization and Disposal of Explosive Material. An important consequence of international agreements to greatiy reduce the stockpiles of conventional and nuclear munitions is the intensification of a program to develop procedures to destroy, recycle, and/or reclaim explosives, propellants, and pyrotechnic material efficientiy and without significant environmental impact. 

The procedures commonly used to demilitari2e conventional munitions iaclude munitions disassembly, washout or steamout of explosives from projectiles and warheads, iaciaeration of reclaimed explosives, and open burning or detonation. Open burning and detonation of large quantities of... 

Pollution Prevention. Procedures haven been developed for recovery of composite ammonium perchlorate propellant from rocket motors, and the treatment of scrap and recovered propellant to reclaim ingredients. These include the use of high pressure water jets or compounds such as ammonia, which form fluids under pressure at elevated temperature, to remove the propellant from the motor, extraction of the ammonium perchlorate with solvents such as water or ammonia as a critical fluid, recrystalli2ation of the perchlorate and reuse in composite propellant or in slurry explosives or conversion to perchloric acid (166,167). 

Potassium Nitrate. Potassium nitrate, known but Httle used as a fertilizer for many years, may be reclaimed as a by-product of the production of sodium nitrate from natural deposits of caflche in Chile. KNO also has been produced by the double decomposition reaction between sodium nitrate and potassium chloride ... 

Used oil disposal trends include waste minimisation such as by reclaiming used fluid on site, as well as recycling of mineral oil lubricants instead of disposing by incineration. The recycling effort involves a system where spent mineral oils are collected then shipped to specialty refineries where the materials are distilled, hydrofinished, and re-refined into fresh base stocks. These re-refined materials are virtually identical to virgin feedstocks. 

Iron ores of different characteristics and compositions can be blended to a more uniform composition. This can be accompHshed during handling operations involved in transporting ore to its point of use, or through special blending faciUties, such as stacking and reclaiming. 

Some of this material is reclaimed by ketde melting and refining. However, most scrap is a combination of metallic lead and its aUoying constituents mixed with compounds of these metals, usuaUy oxides and sulfates. Therefore, recovery as metals requires reduction and refining procedures. 

Because about 80% of the lead consumed in the United States is for use in lead—acid batteries, most recycled lead derives from this source of scrap. More than 95% of the lead is reclaimed. Hence, the bulk of the recycling industry is centered on the processing of lead battery scrap. 

Whereas many of these technologies are not really new, they have never had the regulatory and economic justification for their use in metallizing. Each of these general methods has many variants. Some may be directed to waste treatment, some to recycle, and some to reclaim. An example is filtration, used to prevent release to air of zinc particles from flame spraying, microfiltration of cleaners to extend hfe, in combination with chemical precipitation to remove metal particles from wastewater, and many other uses. 

In addition, many grades of paper and paperboard are used in direct or indirect contact with foods. Thus, many mills only use paper chemicals that have been cleared for use by the U.S. Pood and Dmg Administration (PDA) (3), so that it is not necessary to segregate machine broke (off-grade paper and edge clippings that are reclaimed for their fiber value) and white water. Most of the chemicals discussed in this article are approved by the PDA for use in paper and paperboard that are intended for appHcations in food processing and packaging. However, there are various restrictions on both the specific functional uses and amounts of paper chemical additives which can be used, so the PDA status should be confirmed by the suppHer before use. 

A proprietary form of Caro s acid is sold to the electronics iadustry under the trade name Nanostrip. Used for reclaiming defective siHcon wafers, it is manufactured by Cyantech (United States), Micro-Image Technology (UK), and RASA Industries (Japan). 

By-products of these reactions are reclaimed and recycled. The color depends on the size of the particles formed. Size is controlled by regulating the calcination profile, ie, time and temperature. The calcined product is ground, washed, and classified. 

Phosgene addition is continued until all the phenoHc groups are converted to carbonate functionahties. Some hydrolysis of phosgene to sodium carbonate occurs incidentally. When the reaction is complete, the methylene chloride solution of polymer is washed first with acid to remove residual base and amine, then with water. To complete the process, the aqueous sodium chloride stream can be reclaimed in a chlor-alkah plant, ultimately regenerating phosgene. Many variations of this polycarbonate process have been patented, including use of many different types of catalysts, continuous or semicontinuous processes, methods which rely on formation of bischloroformate oligomers followed by polycondensation, etc. 

Scrap that is unsuitable for recycling into products by the primary aluminum producers is used in the secondary aluminum industry for castings that have modest property requirements. Oxide formation and dross buildup are encountered in the secondary aluminum industry, and fluxes are employed to assist in the collection of dross and removal of inclusions and gas. Such fluxes are usually mixtures of sodium and potassium chlorides. Fumes and residues from these fluxes and treatment of dross are problems of environmental and economic importance, and efforts are made to reclaim both flux and metal values in the dross. 

The recovery of fiber from broke (off-specification paper or trim produced in the paper mill) is compHcated by high levels of urea—formaldehyde and melamine—formaldehyde wet-strength resin. The urea resins present a lesser problem than the melamine resins because they cure slower and are not as resistant to hydrolysis. Broke from either resin treatment may be reclaimed by hot acidic repulping. Even the melamine resin is hydrolyzed rapidly under acidic conditions at high temperature. The cellulose is far more resistant and is not harmed if the acid is neutralized as soon as repulping is complete. 

Photomechanical stencils are of two types direct coatings and transfer films. Direct coatings are either bichromated gelatin or bichromated poly(vinyl alcohol) (PVA). The coated screens are exposed through a positive, washed, and inspected. These screens are used for printing electronic components. They are not practical for commercial work because of the difficulty of reclaiming the screen after use. 

Although more often associated with household and commercial waste, recycling has proven to be very successhil in the industrial arena. Industrial recycling is the recovery for reuse or sale of materials from what otherwise would be wastes destined for disposal (5). Typically, the reclaimable materials employed in industrial recycling may consist of obsolete products, spent materials, industrial by-products or residues, or pollution control products. The recycling of many of these products is so well estabHshed that under standard commercial practices such materials are destined only for recovery, not for disposal. 

P. Mapleston, "Chemical Recycling May be an Option to Meet Reclaim Levels," Modem Plast. (Nov. 1993), courtesy Lexis/Nexis Information Services. 

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