Bulk inorganic chemicals

Even the industrial gas sector may find a use for decanters if the hydrogen economy ever comes into being. The conversion of hydrogen-containing raw materials could be big business in a decade or two. 

The manufacture of titanium dioxide, for example, by the sulphate route, involves the sulphuric acid digestion of the oxide ore (ilmenite), followed by the separation of unreacted solid from the resultant slurry. This is an application for a decanter, made from corrosion-resistant steels, and equipped with full erosion protection. The produced dioxide needs a decanter again for wet size classification. Similar applications occur in the manufacture of phosphoric acids. The decanter will need a high-torque, low-ratio gear box. 

Among the other bulk inorganic chemicals whose manufacture includes the use of a decanter are aluminium and magnesium hydroxides, iron oxides and salts, calcium carbonate and other salts, silicon and silicates, caustic soda, sodium carbonate and other salts, graphite, uranium yellow cake , gypsum, and zinc oxide and salts. Calcium carbonate is a particularly difficult material to treat in a decanter, in that it needs very high torque to achieve an adequate level of cake dryness. 

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The production of wood pulp and paper is a primary industry in the sense of its utilization of wood as its chief raw material. Pulp and paper is also a secondary industry in the sense that it consumes large quantities of bulk inorganic chemicals such as chlorine, sodium hydroxide, sodium sulfate, etc., produced by the primary (commodity) chemical industry. This business area consumes close to 10% of the inorganic chemicals produced in the countries in which it is dominant. Thus, it not only contributes directly to the economy of these areas, but also indirectly by its purchases of chemicals. 

A basic criterion used to select a continuous precipitation process is the amount or the mass rate of product to be manufactured. Bulk inorganic chemical, catalyst, fertilizer, and food processing industries are typical examples of such high-capacity precipitation operations. 

Table 3.1 USA production (billions of lb) of bulk inorganic chemicals ...

The modern heavy (bulk) inorganic chemicals industry is described in the remainder of the chapter but at this stage it may be useful to look at the historical aspects of some of the processes. 

Chemicals - petrochemical feedstocks and intermediates, bulk inorganics, plasticisers, specialty chemicals, fertilisers ... 

Kemira Chemicals chemicals for the pulp and paper industry and water treatment, bulk inorganics and fine chemicals ... 

The production of chlorine and caustic soda is the story of the bulk inorganic commodities chemicals business. It is an example of a large scale manufacturing industry which uses high technology processes to create the basic raw materials used worldwide as the building blocks for industry. 

TfflS SECTION INCLUDES TESTS for determining the materials of construction requirements for equipment used for manufacturing chemicals. This includes both bulk chemicals, which are typically manufactured in dedicated equipment in large quantities, and specialty chemicals, which are most often made in smaller quantities and often in equipment used for more than one process. Tests for both organic and inorganic chemicals eure included. Because some tests require the presence of an electrolyte, they are not suitable for many pure organic processes. Equipment intended for use in the pharmaceutical, petrochemical, or high-temperature gas phase or molten salt processes have special requirements that are not included in this section. 

The preparation methods used to study the morphology of bulk polymers differ from the methods used for inorganic materiais. The usual methods applied to inorganics, chemical or electrolytic thinning, are not applicabie to poiymers because... 

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