Raw Material Examination

A chemical analysis alone cannot describe the form, particle size, or mineralogy of the feed. SiO from a chemical analysis does not necessarily mean quartz, nor does Fe Oj necessarily imply hematite. Analysis by X-ray diffraction (XRD) quite accurately records most of the detectable mineralogical varieties and with calibrated standards allows an estimation of abundance. But XRD cannot elucidate the particle form or size, and virtually misses the occurrence of amorphous materials such as glass or poorly crystalline materials such as limonite, FeO(OH), a major constituent in many iron sources for portland cement. Phases below the detection limit by XRD can easily be seen in the microscope. However, chemical and XRD analyses of each of the raw materials individually, in sieved fractions, and in their blended combination in the feed, are immensely helpful, indeed strongly recommended, for routine 

Consequently, the purposes of microscopical examination of raw materials are to describe the mineralogy, and to estimate the mineral abundances and particle size variations, all of which bears directly on the ease with which the material combines in the kiln. The importance of microscopy can hardly be overstated. 

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The results of the raw materials examination (including the characteristic receiving number), are recorded and. signed by the person in charge of the quality control... 

Certain minerals in cement raw materials examined in thin sections or sieved powders can be selectively stained with a wide variety of liquids (Carver, 1971 Hutchison, 1974) and studied with a stereomicroscope and a petrographic microscope. The stains are normally used to augment data from ordinary optical microscopy. 

Prospective Processes. There has been much effort invested in examining routes to acetic acid by olefin oxidation or from ethylene, butenes, or j -butyl acetate. No product from these sources is known to have reached the world market the cost of the raw materials is generally prohibitive. 

In a modern industrialised society the analytical chemist has a very important role to play. Thus most manufacturing industries rely upon both qualitative and quantitative chemical analysis to ensure that the raw materials used meet certain specifications, and also to check the quality of the final product. The examination of raw materials is carried out to ensure that there are no unusual substances present which might be deleterious to the manufacturing process or appear as a harmful impurity in the final product. Further, since the value of the raw material may be governed by the amount of the required ingredient which it contains, a quantitative analysis is performed to establish the proportion of the essential component this procedure is often referred to as assaying. The final manufactured product is subject to quality control to ensure that its essential components are present within a pre-determined range of composition, whilst impurities do not exceed certain specified limits. The semiconductor industry is an example of an industry whose very existence is dependent upon very accurate determination of substances present in extremely minute quantities. 

The tables that follow give the costs of various SCP production processes in comparative rather than in actual form. To see what this means examine Table 4.9. The production cost of raw materials for yeasts grown on n-alkanes is given as 58.5. This means that tire cost of raw materials accounts for 58.5% of the total production costs of this process. The same cost for bacteria grown on methanol is 73.8. This means that in this case 73.8% of the total production cost is accounted for by raw materials. This does not mean that the actual cost of raw materials for tire methanol process is more titan that for the n-alkanes process, as the total costs of the two processes are not necessarily similar. 

Different methods available for material recycling of plastics waste into raw materials for the chemical industry are reviewed and discussed. The technical problems, energy efficiencies and cost efficiencies of the processes are examined. 35 refs. 

Raw materials or goods which are exported to the USA are subjected to the same restrictions as those which are manufactured within the USA. There is also a duty to ensure that each delivery is authorised by the US customs authorities. Anybody who does not conform to these so-called TSCA (Toxic Substances Control Act) conditions must reckon on a high fine. This article examines in detail all the legal, administrative and financial steps that must be followed before making the first exports, including adhesives. EUROPEAN COMMUNITY EUROPEAN UNION GERMANY USA WESTERN EUROPE... 

Owing to their numerous actual and potential applications, several ternary and complex systems of these metals, especially of aluminium, have been investigated a few examples of the systematics of Al-Me-X alloys are presented in 5.18 and in Fig. 5.41. Recent contributions to this subject have been given with the study of the systems R-Al-Cu (Riani et al. 2005, and references there in). These rare earth alloys, characterized by the formation of several intermediate phases, are interesting also as raw materials for the preparation of amorphous alloys. Regularities in the trends of their properties have been underlined. The experimental and calculated data relevant to the binary systems Al-Fe, Al-Ni and Fe-Ni have been examined and discussed in a paper concerning the assessment of the ternary Al-Fe-Ni system (Eleno et al. 2006). 

To examine an entire process from beginning to end (raw material suppliers to stability of the final product) as a unit operation. With this frame of reference, the important factors in ihe entire process and their effect on each other can be determined. The use of initial screening experiments on each of the individual steps would identify the important factors to include in the overall design. This is the only practical way to determine how the process is going to react at the high and low set points for each of the important factors in the process while the other important factors are at either their high or low set points. 

With regard to the location of innovation systems, however, neither the regional nor the national level (national and regional iimovation systems) could be apphed in the SubChem project due to the subject of examination. A branch approach (sectoral innovation systems) was also not an appropriate way to approach the SubChem project. The iimovation systems examined by SubChem are to be found over the entire supply chain from natural raw material supply and chemicals production to disposal and recychng (innovation systems going beyond supply chains and/or product life cycles). 

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