Relative costs of metals

Table I. The Relative Costs of Metals Active in CO Hydrogenation...

Talbe 7.10 Relative Costs of Metals Using Carbon Steel as the Base Case... 

CEPCI (Chemical Engineering Plant Cost Index), 186. 188 corrosive environments, 202-204 cost data, sources of, 182 equipment cost attribute, 182 equipment summary, PFD, 19-20 inflation adjustment, 186-187 manufacturing vessels, 207-208 Marshall and Swift Equipment Cost Index, 186. 188 MOCs (materials of construction), 202-208 module costing technique, 192-193 pressure factors, 197-202 relative costs of metals, 206 weld efficiency, 198 Capitalized cost, 314 Capitalized cost method, 314-316 Carbon steels, equipment cost, 205 Carnot efficiency, 235 Cascade diagrams... 

An indication of the relative cost of the alkali metals in bulk at 1980-82 prices (USA) is ... 

The relative cost of equipment made from different materials will depend on the cost of fabrication, as well as the basic cost of the material. Unless a particular material requires special fabrication techniques, the relative cost of the finished equipment will be lower than the relative bare material cost. For example the purchased cost of a stainless-steel storage tank will be 2 to 3 times the cost of the same tank in carbon steel, whereas the relative cost of the metals is between 5 to 8. 

Metal ions are generally recovered or removed from aqueous discharges by selective precipitation of their insoluble compounds. One of the most popular precipitating agents is the OH- ion. The addition of commercial bases to wastewaters so as to precipitate and remove insoluble metal hydroxides is a common practice for water treatment. This is a relatively simple operation, and the reagents used (typically lime and soda ash) are inexpensive, safe, and readily available. The approximate relative cost of the commercial bases Ca(OH)2, Na2CC>3 andNaOH is 1 3 5, respectively. 

Although relative metal economy does not necessarily mirror the relative costs of the vessel "in place," Adams reported that "the relative metal cost is a fairly reliable index of the relative total cost." The higher strength steels have more spring-back in bending and require a little more care in welding, but they will also be thinner and require less welding. 

TABLE 3.3. Relative Costs of Some Alkali Metal Hydroxides... 

Certain attributes of the offset lithographic press make it particularly appealing as a means of mass reproduction of printed matter and images. These include extremely high throughput clear, clean, and sharp impressions the much lower cost of metal plates relative to stone plates the ability to handle rough and hard papers low... 

Comparison of relative costs of various metals is not straightforward. Zinc salts (i.e., ZnCl2 and ZnBt2) as well as boric esters and BusSnCl may be judged to be relatively inexpensive. However, value-added B- and Sn-containing compounds, such as various hydridoboranes, B—B bond-containing compounds, McsSnCl, and distannanes... 

Polypropylene composites have many advantages over metal such as corrosion resistance, low weight, easily molded complicated shapes, and low cost. A 1979 article (1), compared the cost of polypropylene composites versus steel sheet at equal stiffness (Table 14.1). Mica-filled (40 wt%) polypropylene was the only composite with a relative cost less than that of steel (0.98) for a part with stiffness equal to steel. The relative thickness of the composite was 2.88 and the relative weight was 0.45. Cost calculations were based on mica at 0.18/ lb and polypropylene at 0.31/lb. The relative cost of a 40% glass-filled polypropylene composite was 2.48 and its relative weight was 0.49. The relative cost of a 40 wt% filled talc/polypropylene composite was 1.32 and the relative weight was 0.61. 

In practice the mass ratio of magnesium to calcium used is between 2 1 and 4 1, and depends on the relative cost of the reagent metals. The process is promoted by the addition of antimony, which can also form intermetallic compounds as a replacement for bismuth, and is necessary to achieve low levels of residual bismuth. It is suggested that the antimony compound is isomorphous with the bismuth compound and a solution of the two causes a lowering of the activity of the bismuth complex (Moodie, 1976). 

The diffusion coating process is one of the most effectively and with a great practical application method for improvement of corrosion resistance together with wear resistance, hardness and working live of metals and alloys. This is very important for the carbon steels as the most widely used engineering material accounts more than 80% of the annual world steel production. Despite its relatively limited corrosion resistance, carbon steel has a wide application in whole nowadays industry and the cost of metallic corrosion to the total... 

It should be pointed out that the density of hydrogen in the metal hydride is similar to that of liquid Ha, implying that hydrogen in the metal is in an atomic form. This has been verified by other methods. The relative cost of the various storage systems is estimated in Table 6.10, but this too will greatly depend on the quantities involved. 

Moreover, information about the cost of materials presented in this text is limited to a few different MOCs. The approximate relative cost of some common metals is given in Table 7.10. As a very approximate rule, if the metal of interest does not appear in Appendix A, then Table 7.10 can be used to find a metal that has approximately the same cost. As the metallurgy becomes more exotic, the margin for error becomes larger, and the data provided in this text will lead to larger errors in estimating the plant cost than for a plant constructed of carbon steel or stainless steel. 

As the cost of metals and other traditional materials increases, so the cost of the cheaper thermoplastics become increasingly competitive. Even more important is the relative simplicity of the injection moulding, film blowing or extrusion operation which, to a large extent, determines the cost of the fabricated article. As further improvements in the productivity of plastics fabrication equipment continue to be made it seems likely that, assuming the problem of disposal can be overcome, plastics will become increasingly dominant in the packaging industry in the future. 

The extraction of titanium is still relatively costly first the dioxide Ti02 is converted to the tetrachloride TiCl4 by heating with carbon in a stream of chlorine the tetrachloride is a volatile liquid which can be rendered pure by fractional distillation. The next stage is costly the reduction of the tetrachloride to the metal, with magnesium. must be carried out in a molybdenum-coated iron crucible in an atmospheric of argon at about 1100 K ... 

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