Water white

White pine White rust White s agar White Shoulders White smoke Whitewares Whitewash White water Whitfield s Ointment... 

Sn(BF )2 XH2O [72259-13-3] white water Sn(BF4)2 SnF2 5H20 crysta11i2es from... 

Fluoroacetamide. Fluoroacetamide [640-19-7], FCH2CONH2, is a white water-soluble soHd having mp 108°C (14). It has been used as a rodenticide and has been reported to have a better acceptability to rats than sodium fluoroacetate (29). However, like the latter compound, its misuse has caused deaths to farm animals and pets (20). 

Mercuric Acetate. Mercuric acetate/7ti(9(9-27-7/, Hg(C2H202)2, is a white, water-soluble, crystalline powder, soluble in water and many organic solvents. It is prepared by dissolving mercuric oxide in warm 20% acetic acid. A slight excess of acetic acid is helpful in reducing hydrolysis. 

Modem practice is to maintain the white water system as closed as possible, ie, as much water as is compatible with efficient machine operation is recycled. The loss of fibers and inert furnish components, particularly clay, has been gready reduced. Eiber losses, however, stiU occur into the white water, and greater economy of operation may be achieved if these fibers could be recovered. Thus, it is common to design a fiber-recovery system into the white water cycle. The three general types of save-all fiber recovery are based on filtration (qv), dotation (qv), and sedimentation (qv). If these are operated efficiendy, the net fiber loss can be less than 1%. 

The use of these sHmicides may result in an appreciable increase in the cost of producing paper. However, thein use often reduces downtime that is caused by slime and, therefore, increases production which more than compensates for the initial cost of the sHmicides. White water systems also often contain proteolytic microorganisms which attack the machine felts and reduce thein useful life. Control of this problem may be accompHshed by treating the felts with a sHmicide foUowed by cleaning with a mild acid (see INDUSTRIALANTIMICROBIALAGENTS). 

In addition, many grades of paper and paperboard are used in direct or indirect contact with foods. Thus, many mills only use paper chemicals that have been cleared for use by the U.S. Pood and Dmg Administration (PDA) (3), so that it is not necessary to segregate machine broke (off-grade paper and edge clippings that are reclaimed for their fiber value) and white water. Most of the chemicals discussed in this article are approved by the PDA for use in paper and paperboard that are intended for appHcations in food processing and packaging. However, there are various restrictions on both the specific functional uses and amounts of paper chemical additives which can be used, so the PDA status should be confirmed by the suppHer before use. 

It is also important to study the interactions of papermaking additives (4) in the paper machine water system some additives act synergisticaHy, so that the performance of each is enhanced by the presence of the other. However, some additives have a negative impact on the performance of other additives, or on other desirable paper properties. Thus, optimization of the addition points and usage rates of the entire additive system is necessary in order to maximize performance of the chemical additives and the paper sheet properties, and to minimize cost and negative interactions both on the paper machine and in the white-water system. This is especially tme as unanticipated additives enter the wet end of the paper machine from recycled furnishes, including coated broke (5). 

Water Clarification. Process water that aeeds to be clarified comes from several differeat sources ia the recycling mill rejects from screeas and mechanical cleaners rejects from washers, thickeners, and flotation cells water that drains from the pulp as it is converted iato paper oa the paper machine (white water) and water from felt washers. These waters contain different dissolved chemicals and suspended soflds and are usually processed separately. 

Zinc Dithionite. Zinc dithionite [7779-86-4] is a white, water-soluble powder. Although it exhibits somewhat greater stabiHty in... 

Recirculation. In the paper board industry, white water from a paper machine can be put through a saveaH to remove the pulp and fiber and then be recycled to various points in the paper-making process. 

Observable Characteristics - Physical State (as normally shipped) Solid Color White water solutions may be dyed blue Odor None. 

The solution was filtered and evaporated in vacuum over concentrated sulfuric acid. The sodium salt is then obtained as a creamy white water-soluble solid. Glycyrrhetinic acid is obtainable from licorice root. 

White waters from pulp screening, thickening, and cleaning... 

Almost all fiber and partial titanium dioxide can be recovered from white water by DAF under full flow pressurization mode43 with chemical addition. On June 10, 1982, at Mead Corporation, pulp was prepared with 40% cotton fiber and 60% wood fiber. The loading of titanium dioxide was about 50% (i.e., 273 kg Ti02 per 600 kg total pulp). The white water from No. 2 machine was fed to a DAF cell (diameter = 3 m) at 15.8 L/s (250gal/min) under full flow pressurization mode. Turkey red oil (TRO) was dosed as a flotation aid at 80mL/min. The influent white water (before TRO addition), DAF effluent, and floated scum were sampled for analysis. The DAF influent had 98 mg/L of TSS, and 650 NTU of turbidity at pH 9.27. The DAF effluent had 15 mg/L TSS and 550 NTU of turbidity at pH 9.25. Although TSS (fiber and titanium dioxide) recovery rate was 85%, the ash content (titanium dioxide) of the recovered TSS was very low. Therefore, using a DAF clarifier under full flow pressurization mode and TREO, the majority of fibers in white water but only about half of titanium dioxide can be recovered. 

A separate continuous DAF operation conducted by Krofta and Wang59 under 33.3% recycle flow pressurization mode demonstrated that aluminum sulfate, sodium aluminate, and polyelectrolyte combination at pH 6.2 also effectively recovered both fibers and titanium dioxide from the same white water containing 500mg/L of titanium dioxide and 1000 mg/L of cotton fibers. 

It is enough to visit the clean, small production plant of Sol-Gel Technologies in Israel (Figure 8.3) to recognize that most of the value added to benzoyl peroxide entrapped in microcapsules comes from knowledge—and thus from human ingenuity—which originates the production of the microcapsules. The price at which the white water-based capsule formulation is sold to customers exceeds more than 1000 times the price of the raw materials used to prepare it. Put another way ... 

Figure 6.5 Lignin structures identified in extracts from the white water from a newsprint machine.

A low consistency suspension of fibres, pigments and chemical additives (thin stock) flows on to the moving wire mesh filtration medium of the paper machine where the wet web is formed. The water which drains away in this process (white water) is then recycled as far as it is practical to do so and is used to dilute the incoming high consistency suspension (thick stock). Retention can be considered either in overall terms or in terms of a single pass of the thin stock across the machine wire (first pass retention). For efficient operation, paper makers aim to achieve as high a first pass retention as possible, which they do by the use of retention aids. This reduces material losses and also assists in minimising the level of suspended solids in the effluent. 

The zinc sulphate produced in this process can be turned more easily to commercial account than iron sulphate. If to the solution of the zinc sulphate resulting from the process sodium carbonate or sodium hydrogen carbonate is added, a precipitate of hydrated zinc basic carbonate or zinc carbonate is obtained, which on ignition in a furnace yidds zinc oxide (commercially known as zinc white ), water, and carbon dioxide. Zinc white has a commercial value as a basis or body In paints it has one great advantage over white lead, which is used for the same purpose, in that it is far less poisonous. This method of treatment of the residual... 

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