Paper Pulp Products

3 Tar Oil and Paper Pulp Products 2.3.1 Paper Pulp Products 

Paper pulp products refer to the sulfate soaps which are separated ftom the black liquor of paper pulping. The components of paper pulp products are unsteady. For instance, the components of domestic paper pulp product are listed as follows  

In general, fatty acids and resin acids are the active ingredients. The content of fatty acids or resin acids is about 10-20 %. Fatty acids are mainly comprised of saturated acids such as oleic acids, Unoleic acids, and linolenic acids, and a spot of unsaturated acids such as those with C5-C24. Resin acids are mainly comprised of dehydroabietic acids, and dihydro- and terealin abietic acids. 

In addition, some impurities such as cellulose and lignin exist in the product. Because these impurities perform depressing capability in the flotation of some minerals, these impurities are usually considered as detrimental impurities. 

Compared with oleic acids, the application characteristics of paper pulp products in the flotation of oxide mineral can be given by the following  

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I.4. Polyterpene resins. Terpene resins are obtained from natural terpene monomers obtained from naval stores, paper pulp production, and citrus juice production. Terpenes are found in almost all living plants, and the turpentine oil from pine trees is the most important source. 

Paper pulp products are characterized by unstable composition. Therefore, flotation performance of reagent obviously varies with the change of source. 

The content of active ingredient of paper pulp product is too low. Therefore, the collecting performance of paper pulp product is not good. And the dosage is relatively higher. 

Paper pulp products usually contain a specified volume of detrimental impurities. 

The foam is too viscous when paper pulp product is used in industry. 

By far, paper pulp products are rarely employed in industry. 

The components of several foreign crude tar oils are found in Tables 2.4 and 2.5. The flowchart of crude tar oils is shown in Fig. 2.2. The content of active ingredient of crude tar oils is twice as much as that of paper pulp products. And the component of crude tar oils is relatively steady. Therefore, the flotation performance of crade tar oils is relatively better. It should be pointed out that however, the contents of unsaturated fatty acids and resin acids are relatively higher. Therefore, the frothing capacity of crude tar oils is so high that cmde tar oils are hard to be applied in industry. 

Meanwhile, similar diseases had been discovered at a number of locations around the world. A friend of this author visited a number of these places and found that they were indeed Minamata disease. In most of those places, the sources of mercury appeared to be chentical plants, particularly associated with paper/pulp mills. The chemical plant in Minamata was not involved in the paper/pulp production instead they were producing acetaldehyde. 

The isolation of chemicals from Kraft lignin, the polymer by-product of the Kraft pulping process for paper production, is an established industrial process [219]. There have been several studies on alternative degradation processes such as hydro-genolysis [220], biodegradation with white-rot fungi [221], and chemical oxidation [121,122,222]. These processes can in principle be used with residual lignin obtained from vine shoots employed for paper pulp production. 

Pulp production and per capita consumption of paper and board for 1992 is shown in Table 8. The United States, Canada, Sweden, Finland, and Norway make up the North American and Scandinavian (NORSCAN) countries and produced about 63% (22.8 million tons) of the world output. Market share is growing for producers in Latin and South America, Western Europe, Asia, and Africa. These areas provide low cost pulp from state-of-the-art mills. Mills in the third world countries often enjoy the benefits of plentiful, fast-growing tree species, such as eucalyptus and tropical pines, and lower operating and labor costs (3). 

The United States is the largest importer of pulp, in 1993 importing 5.5 million tons, principally bleached and semibleached kraft pulp. It is also the largest producer of pulp, paper, and aUied products. Table 9 shows U.S. pulp production for 1983—1992. 

Natural resins were probably known to early people, who recognized them as exudates from trees. Collection and use of these resins have been recorded by early Roman and Greek historians. Many products have been collected by the same methods throughout history to the present time. However, increased labor costs and competition from synthetic resins have reduced the demand for some natural resins, so they have become less available. In other cases, such as that of rosin, the traditional collection of gum from trees has been supplemented or replaced by isolation from other sources, such as paper pulping and tree stumps. 

As of the mid-1990s, soluble sihcates are used primarily as sources of reactive siUca (57%), in detergency (qv) (23%), in pulp (qv) and paper (qv) production (7%), for adhesives and binders (5%), and in other appHcations (8%). The stmcture and chemistry of solutions containing polymeric siHcate species have been characterized using modem analytical techniques. This improved understanding of siHcate speciation contributes to the development of new markets. Thus, the sodium silicates constitute a versatile, stable, and growing commodity and are ranked among the top 50 commodity chemicals. 

Paper Products. Paper (qv) products account for about 2% of sulfur demand. The largest single segment of demand is in the manufacture of wood pulp by the sulfite process (see Pulp). In this process, the main sulfur intermediate is sulfur dioxide, which is generally produced at the plant site by burning elemental sulfur. Some sulfur dioxide, however, is produced as a by-product at smelter operations, purified andUquefied, and shipped to the pulp mills. The sulfur dioxide is converted to sulfurous acid, and the salt of this acid is a principal component of the cooking Hquor for the sulfite process. 

Titanium metal is especially utilised ia environments of wet chlorine gas and bleaching solutions, ie, in the chlor—alkaH industry and the pulp and paper industries, where titanium is used as anodes for chlorine production, chlorine—caustic scmbbers, pulp washers, and CI2, CIO2, and HCIO storage and piping equipment (see Alkali and cm ORiNE products Paper Pulp). 

Sodium Tetrahydroborate, Na[BH ]. This air-stable white powder, commonly referred to as sodium borohydride, is the most widely commercialized boron hydride material. It is used in a variety of industrial processes including bleaching of paper pulp and clays, preparation and purification of organic chemicals and pharmaceuticals, textile dye reduction, recovery of valuable metals, wastewater treatment, and production of dithionite compounds. Sodium borohydride is produced in the United States by Morton International, Inc., the Alfa Division of Johnson Matthey, Inc., and Covan Limited, with Morton International supplying about 75% of market. More than six million pounds of this material suppHed as powder, pellets, and aqueous solution, were produced in 1990. 

Enzymes in Pulp and Paper Production. Enzyme-modified starch has been used for adhesives to strengthen paper base and for surface coating. Developments since the late 1980s of further uses of enzymes in papermaking include pitch control and bleach boosting, (see Paper Pulp). 

Because of the lack of solubility in the usual solvents, aniline-formaldehyde laminates are made by a pre-mix method. In this process the aniline hydrochloride-formaldehyde product is run into a bath of paper pulp rather than of caustic soda. Soda is then added to precipitate the resin on to the paper fibres. The pulp is then passed through a paper-making machine to give a paper with a 50% resin content. 

Venmri scrubbers have been applied to control PM emissions from utility, industrial, commercial, and institutional boilers fired with coal, oil, wood, and liquid waste. They have also been applied to control emission sources in the chemical, mineral products, wood, pulp and paper, rock products, and asphalt manufacrnring industries lead, aluminum, iron and steel, and gray iron production industries and to municipal solid waste incinerators. Typically, venturi scrubbers are applied where it is necessary to obtain high collection efficiencies for fine PM. Thus, they are applicable to controlling emission sources with high concentrations of submicron PM. 

In the pulp and paper industry, the main gas emissions are from the pulp production. The main sources of emission are in the soda recovery boiler, lime kiln, evaporation plant, and bark combustion boiler. 

World production expressed as 100% H2O2 approached 1.9 million tonnes in 1994 of which half was in Europe and one-fifth in the USA. The earliest and still the largest industrial use for H2O2 is as a bleach for textiles, paper pulp, straw, leather, oils and fats, etc. Domestic use as a hair bleach and a mild disinfectant has diminished somewhat. Hydrogen peroxide is also extensively used to manufacture chemicals, notably sodium perborate (p. 206) and percarbonate, which are major constituents of most domestic detergents at least in the UK and Europe. Normal formulations include 15-25% of such peroxoacid salts, though the practice is much less widespread in the USA, and the concentrations, when included at all, are usually less than 10%. 

Titanium is being employed in the bleaching industry where the good corrosion resistance of the material makes it particularly suitable for equipment in both textile and paper pulp bleaching processes. In the dye-stuffs industry, the inertness of titanium eliminates any products of corrosion which might cause discoloration of the products. A similar situation can also exist in areas like the plastics, pharmaceuticals, and food-stuffs industries. 

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