Economic significance

The consumption of surfactants in Western Europe is estimated to be more than 1 million tons/year. As shown in Fig. 10, about 60% of this quantity are anionic surfactants (above all LAS), and the remainder is divided into about V4 of nonionics and % of cationics or amphoteric surfactants. 

The economic significance and the application in many fields should be demonstrated once more by reference to the list below, where the specific purposes of the surfactants are also shown alongside the fields of use (Table 6). 

By far the major part of the surfactants manufactured is consumed by detergents and cleaning agents. The widely different quantities consumed, depending on 

Laundry detergents, dishwashing detergents, household cleaners Industrial cleaners, floor cleaners, commercial laundry Shampoos, cosmetics 

At present, the value of the surfactants marketed in Western Europe is estimated to be about 8,000 million DM/year. 

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Table 4 gives typical analyses of some of the commercial manganese ores available ia the world market. Table 5 gives a breakdown of the world s total estimated manganese ore reserves that account for 98—99% of the known world reserves of economic significance. No manganese ores of commercial value are to be found ia the United States. 

There are approximately 250 known manganese minerals. The primary ores which typically have a Mn content >35%, usually occur as oxides or hydrated oxides, or to a lesser extent as siUcates or carbonates. Table 5 Hsts the manganese-containing minerals of economic significance (10). Battery-grade manganese dioxide ores are composed predominately of nsutite, cryptomelane, and todorokite. 

Research in catalysts for ammonia manufacture is stiU going on, and though the use of supported metals such as mthenium may be two to three times as active as promoted iron oxide, catalysts 50—100 times more active than promoted iron oxide are required to affect process economics significantly. 

The sodium salt of CS [9005-22-5] is prepared by reaction of cellulose with sulfuric acid in alcohol followed by sodium hydroxide neutrali2ation (20). This water-soluble product yields relatively stable, clear, and highly viscous solutions. Introduced as a thickener for aqueous systems and an emulsion stabilizer, it is now of no economic significance. 

Whereas certain rocks of igneous origin formed by melting and recrystallization can include minerals enriched in the lanthanides (4), cerium is usually present as a trace element rather than as an essential component. Only a few minerals in which cerium is an essential stmcture-defining component occur in economically significant deposits. Two minerals supply the world s cerium, bastnasite [68909-13-7] LnFCO., and monazite [1306-41 -8] (Ln,Th)PO. ... 

Coumaria is the parent substance of a large group of derivatives, many of which occur naturally and some of which are of economic significance. 

A large number of coumatin derivatives have been identified in plants and many of them have been synthesized and studied for their physiological activity. Only a few are mentioned here because of their economic significance. 

The discovery and use of metals at the end of the Stone Age was one of the most important steps in the development of modem technology. Most base metals are, unfortunately, not stable. In unfavorable environments they can be destroyed at variable rates by corrosion. The study of such corrosion reactions and the methods by which corrosion of metals can be fought is a task of great economic significance. 

Table 1.18 Major uranium resources of the world numbered in sequence on the basis of their geological setting and arranged according to their approximate economic significance.

Depending upon lithologic and structural relationship with host rocks, mineralogy, attendant alteration, paragenesis and spatial and temporal constraints, the uranium resources of the world can be assigned to the 15 main categories of uranium ore deposits. They have been shown numerically numbered in sequence in the order of their approximate economic significance in Table 1.18. At present, only 7 can be said to be economically important (see Table 1.19) and these account for more than 95% of the world resources of ura-... 

Precious Metals Recovery Metal recovery units engaged in precious metals recovery are also conditionally exempt from Part 266, Subpart H. Precious metal recovery is defined as the reclamation of economically significant amounts of gold, silver, platinum, palladium, iridium, osmium, rhodium, ruthenium, or any combination of these metals. Provided the owner/operator complies with the alternative requirements, the unit would be exempt from all BIF requirements except for the regulations concerning the management of residues. 

Coccidiosis is an economically significant respiratory disease of fowl. During the course of studies directed toward antimalarial agents, sulfani-tran (143) was prepared and found to be a coccidiostat. It is prepared conveniently by reaction of p-aceto-amidobenzenesulfonyl chloride with p-nitroaniline in acetic acid.68... 

The corrosion of iron represents an electrochemical reaction of huge economic significance, accounting literally for billions of dollars of waste every year. The phenomenon has been investigated since the time of Faraday and still presents many controversial and puzzling aspects which only the arrival of in situ spectroscopic techniques has begun to clarify. 

A commonly used catalyst in this process consists of ZnO and Cu. Because methanol is a widely used solvent and fuel, the reaction is economically significant. 

The NICO deposit is located at the south end of the GBMZ in the Proterozoic Bear Structural Province of the Canadian Shield, about 160 km northwest of Yellowknife, Northwest Territories (Fig. 1). It represents an economically significant source of Co-Au-Bi-Cu-Fe with calculated reserves of 21.8 Mt with 1.08g/t Au, 0.13%Co and 0.16% Bi (Fortune Minerals 2008). Mineralization at NICO consists of a number of mineral showings predominantly hosted in brecciated and altered siltstone and wacke of the 1.88 Ga... 

The polymerisation of isobutene by aluminium chloride is certainly the most widely known example of a cationic polymerisation it has been studied for nearly forty years, and until recently it was the only cationic polymerisation which, in the form of the Butyl process, was of major economic significance. However, despite its antiquity and industrial importance the number of fundamental studies devoted to its exploration, and indeed the number of... 

The mechanism of initiation of cationic polymerisations by metal halides was clarified and systematized to some extent by the discovery of the phenomenon of co-catalysis or co-initiation. But, whereas there was, by the mid-1960s, good evidence that at any rate in many systems the halides of boron, titanium, and tin required a co-initiator, the position with regard to the best-known and most popular initiator, and the one which was of greatest economic significance, aluminium chloride, remained obscure. Of the vast number of published experiments on the system, aluminium chloride + isobutylene, hardly any could provide evidence concerning the initiation reaction, because they were almost exclusively concerned with measurements of yields and degree of polymerisation (DP). 

This selective toxicity of the larvae s weapon suggests practical applications. Western subterranean termites are economically significant pests, considered to be the most destructive of all California termites. A pesticide directed specifically against them and harmless to other creatures would be environmentally friendly and extremely useful. Exterminators could rid a house of termites without endangering the residents or destroying beneficial insects. The chemical nature of this toxin is still unknown. We can only wonder what substance can rapidly paralyze one kind of termite and leave other insects unscathed. 

Apart from the economic significance of such loss there are potentially adverse effects on the environment arising from acidification of rain and soil. Ammonia may react with hydroxyl radicals in the atmosphere to produce NOx contributing to the acidification of rain (4). Wet and dry deposition of NH3/NH4+ inevitably contributes to soil acidification through their subsequent nitrification. This effect can be accentuated in woodland by absorption of aerosols containing NH4+ within the canopy followed by transport to the soil in stem flow (5). In more extreme cases, NH3 emission from feedlots, pig and poultry... 

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