Cement Additive

Silica to reduce or prevent high-temperature strength retrogression Dispersants 

Fluid loss additives Antigas migration agents Antifoam and defoaming agents 

Additives and mixtures to reduce or prevent lost circulation Density-increasing or weighting agents Free water control and solid suspending agents Spacers and chemical washes or preflushes Specialty cement blends 

---

Polyacrylamides are used in many other oilfield appUcations. These include cement additives for fluid loss control in well cementing operations (127), viscosity control additives for drilling muds (128), and fracturing fluids (129). Copolymers [40623-73-2] of acrylamide and acrylamidomethylpropanesulfonic acid do not degrade with the high concentrations of acids used in acid fracturing. 

Styrene—Butadiene Latex. SB latex is used in coatings, carpet backing, paper adhesives, cement additives, and latex paint. 

Minor and potential new uses include flue-gas desulfurization (44,45), silver-cleaning formulations (46), thermal-energy storage (47), cyanide antidote (48), cement additive (49), aluminum-etching solutions (50), removal of nitrogen dioxide from flue gas (51), concrete-set accelerator (52), stabilizer for acrylamide polymers (53), extreme pressure additives for lubricants (54), multiple-use heating pads (55), in soap and shampoo compositions (56), and as a flame retardant in polycarbonate compositions (57). Moreover, precious metals can be recovered from difficult ores using thiosulfates (58). Use of thiosulfates avoids the environmentally hazardous cyanides. 

Industrial uses make up most of the market for cyanamide. Calcium cyanamide is used directly for steel nitridation (34) and to some extent for desulfurization (36) (see Steel). Cyanamide is used to produce cationic starch (36) and calcium cyanide. Cyanamide is, of course, the raw material for dicyandiamide and melamine. New uses include intermediates for pesticides, detergents (37), medicines such as antihistamines, hypertension, sedatives, contraceptives, etc (38), the photography industry (39), as an additive for fuels and lubricants, as a paper preservative, and as a cement additive. 

Cementing Principles 1179. Properties of Cement Slurry 1183. Cement Additives 1193. 

The volume of slurry that results from 1 sack of cement additives is defined as the yield. The yield (ft /sack) is... 

Nearly all materials that are added to a cement slurry require the addition of additional water to the slurry. Table 4-160 gives the additional requirements for the various cement additives [167]. 

Pozzolan. Diatomaceous earth is a type of pozzolan. Pozzolan refers to a finely ground pumice or fly ash that is marketed as a cement additive under that name. The specific gravity of pozzolans is slightly less than the specific gravity of cement. The water requirements for this additive are about the same as for cements. Only a slight reduction in specific weight of a slurry can be realized by using these additives. The cost of pozzolans is very low. 

API Standard lOA API Specifications for Oil-Well Cements and Cement Additives, April 1969. 

The updated situation of Recycling Thermoset Composites in Japan is diseussed. The dismantling or cutting up of ships, baths, water tanks, and automotive parts are eovered. Recyeling methods include pyrolysis and incineration. Details are also given of uses for recycled materials such as automotive parts, building materials and cement additives. 18 refs. 

Lignin amines with high nitrogen content are water soluble at both alkaline and acidic pH values. The lignin amines have various useful properties. For example, they are active as flocculants, filtration aids, scale inhibitors, fluid loss additives, oil well cement additives, and corrosion inhibitors among other potential uses. The nitrogen is introduced into the lignins with the Mannich reaction [1570]. 

The major potential uses of wastes in cementing technology are summarized in Table 10-16. There are many Russian patents dealing with the use of wastes from the production of organic chemicals as cement additives. 

---