Calcium sulfate INDEX

Alternative refractive index of 1.523 for dihydrate and 1.575 for anhydrous calcium sulfate. 

Calcium—In general, calcium (as CaCOs) below 800 ppm should not result in calcium sulfate scale. In arid climates, however, the critical level may be much lower. For calcium carbonate scaling tendencies, calculate the Langelier Saturation Index or the Ryznar Stability Index. 

Sulfate minerals in clinkers, observed as floating particles in refractive index oil, were said to occur abundantly in underbumed clinker. Opti cal characteristics of clinker sulfates compared with sulfate phases formed in the laboratory led to the conclusion that the low-index mineral in clinker is an alkali sulfate with a variable but small amount of calcium sulfate held in solid solution. 

As is shown in Figure 3.14, KH-550 has the best modification effect on calcium sulfate whiskers with an activation index (99.6%) higher than that of other coupling agents. The sample modified with KH-550 cannot be wetted by water. Figure 3.15 shows the modification results of calcium sulfate whiskers affected by KH-550 concentration. Modification results become much better with an increase of KH-550 concentration. But the rising trend of activation index is no longer obvious when the concentration of KH-550 is more than 8 wt%. 

Alabaster is also listed in the Colour Index (1971 Cl lll ili Pigment White 25) as a source of calcium sulfate. 

Calcium group Calcium sulfates group Calcite Calcium sulfate, gypsum type Gypsum Hematite De espejuelo Colour Index (1971) 77231 Fishwick (1795-1816) 58, 60-63, 76-77 Pacheco (1638) Bk 3, Vll, 120 Veliz (1986) 209, n.l06... 

According to Bersch (1901), lime green is a mixture of copper arsenite and calcium sulfate. Lime green is also Usted under Colour Index (1971) reference Cl 77412 patent green (q.v.) was apparently synonymous. 

Calcium sulfates group Copper arsenite group Patent green Bersch (1901) 250 Colour Index ( 91 ) 77412... 

Figs 9.9 and 9.10 can be used to obtain K, Pca and PaDc for the stability index. Similar indices may be used to predict bariiun sulfate or strontium sulfate or calcium sulfate deposition. If the product of concentration of Ca ions and SO4 ions exceeds the solubility products ( p) of CaS04, calcium sulfate would be precipitated. The solubility of calcium sulfate decreases with an increase in the temperature. CaCOj and CaS04 scaling cause major problems in plants and equipment encountering salt water. 

The remaining individually indexed eompounds are Almninium, 0048 Ammonimn phosphinate, 4554 Barimn phosphinate, 0210 t Benzaldehyde, 2731 1,4-Benzenediol, 2333 =N Bis(hydrazine)tin(ll) ehloride, 4070 Calcium acetylide, 0585 Calcium phosphinate, 3931 Chromium(Il) ehloride, 4052 Chromium(ll) oxide, 4241 Chromium(ll) sulfate, 4244 Copper(I) bromide, 0265 Diacetatotetraaquoeobalt, 1780 Diisobutylalmninimn hydride, 3082 t 1,2-Dimethylhydrazine, 0955... 

Clarification by removal of casein with such agents as calcium chloride, acetic acid, cooper sulfate, or rennin has often been employed to obtain a serum more suitable for refractometric measurements. Obviously the composition, and hence the refractive index, of such sera will depend on the method of preparation. Furthermore, some of the serum proteins may be precipitated with the casein by some of the agents used, particularly if the milk has been heated. Refractive index measurements of such sera are not generally considered as satisfactory as freezing point measurements for detection of added water (David and MacDonald 1953 Munchberg and Narbutas 1937 Schuler 1938 Tell-mann 1933 Vleeschauwer and Waeyenberge 1941). Menefee and Overman (1939) reported a close relation between total solids in evaporated and condensed products and the refractive index of serum prepared therefrom by the copper sulfate method. Of course, a different proportionality constant would hold for each type of product. 

The program calculates total dissolved solids (TDS), conductivity, and the Langelier and Stiff-Davis Saturation Indexes (see Chapter 3.9). The screen allows the designer to use sodium, calcium, magnesium, chloride, sulfate, or bicarbonate to balance the water analysis. Water quality for up to five feed streams can be entered and blended together to make the total, combined feed water to the system. 

Table 15.2 lists the saturation indexes for the untreated feed water, feed water with 10.2 ppm antisealant, and 4.2 ppm of antisealant plus 3.4 ppm sulfuric acid for pH reduction form 8.1 to 7.5. As the untreated water shows, the major species of concern are the calcium carbonate, barium sulfate, and calcium phosphate. The antisealant does a good job with all but the calcium phosphate. To address this potential scale, acid must be added. This reduces the antisealant demand by 60%. 

The patterns from the calcium salts of heparin are different from those from the sodium salt form. The layer-line spacing is 1.68 nm, with meridional reflections on even layer-lines. The unit cell is orthorhombic. The same pattern also occurs in the calcium salt of heparin sulfate,23 which indexes with an orthorhombic unit cell having a = 1.70 nm, b = 1.27 nm, and c = 1.68 nm. 

Freezing of waters in the active zone over winter results in the progressive concentration of the residual solution, until first carbonates, then sulfates and chlorides/nitrates precipitate out of solution. These salts can be scavenged by the first waters of the thaw, and these may also become concentrated solutions of chlorides/ nitrates and sulfates in the first instance. Thereafter, both secondary and primary carbonate can be scavenged, since, as Ca concentrations decline, the saturation index of calcium carbonate becomes negative. Hence, groundwaters in proglacial areas may span the spectrum from relatively... 

Filler Opacify compound, increase hardness, reduce cost Changes refractive index and reflective properties, adds bulk to compound Calcium carbonate, magnesium carbonate, barium sulfate, carbon or glass fibres... 

The solubility of elements in freshwater is limited and the solubility of calcium and magnesium carbonates are of particular importance in freshwaters. The solubility of carbonates is inversely proportional to the temperature of the water. In other words, as the water temperature increases, calcium and magnesium carbonates become less soluble. If the solubility decreases sufficiently, carbonates will precipitate and form a scale on the surfaces of the system. This scale can provide a protective barrier to prevent corrosion of the metallic elements in a system. Excessive scale deposits can interfere with water flow and heat transfer. The quality of the scale is dependent on the quantity of calcium that can precipitate as well as water flow and the chloride and sulfate content of the water. The tendency of water to precipitate a carbonate scale is estimated from corrosion indices such as the Langelier Saturation Index (LSI) and Caldwell-Lawrence calculations [6-8] which use calcium, alkalinity, total dissolved solids, temperature and pH properties of the water. Other indices, such as the Ryznar Index... 

Naturally occurring alum or rock alum is an important ore of aluminium and is used in numerous manufacturing processes. It is also used as a mordant in the dye industry. Commercial aluminium sulfate is also known as cake alum or patent alum. There is also an aluminium sulfate mineral, alunogen. Ettringite forms primarily as a component of hydrauhc lime plasters. It is also hsted as calcium sulphoaluminate in the Colour Index as Cl 77235/Pigment White 33. 

Calcium carbonates group Barium sulfate Colour Index (1911) 77122... 

Composition given by the Colour Index (1971 Cl 77235/Pigment White 33) as 3Ca0.Al203.3CaS04.31H20 (calcium aluminium oxide sulfate hydrate). 

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