Slurry additives

A cement slurry additive consisting of methylcellulose, melamine-formaldehyde resin, and trioxane has been proposed for better bonding of cement to the casing string [20]. Bisphenol-A epoxide resins, with amine-based curing agents, sand filler, and a mixture of n-butanol and dimethyl benzene as a diluent, have been proposed as additives to increase adhesion properties of cement [572]. 

Thermodynamic inhibitors Antinucleants Growth modifiers Slurry additives Anti-agglomerates Methanol or glycol modify stability range of hydrates. Prevent nucleation of hydrate crystals. Control the growth of hydrate crystals. Limit the droplet size available for hydrate formation. Dispersants that remove hydrates. 

Paper is placed in a hydropulper, a large water tank equipped with a heavy motor-driven propeller at the bottom. The propeller agitates the water and wet paper and separates the paper fibers into a fiber slurry. Additives are added and mixed as needed at this point. This is a batch process and as such requires more than one hydropulper in order to be processing one tank as another is being emptied of slurry and refilled with water. The slurry is pumped into a box having a large-diameter cylinder covered by a wire screen rotating slowly within it. Fibers are deposited on the screen as water is pumped out of the screen and returned to the process. The fiber mat is carried up and over as the screen rotates and then transferred to a flat wire screen belt which moves the mat across suction boxes and onto the dryers. 

There have been some efforts in slurry recycling to reduce CoO of CMP consumables. In a recent study [37], the effluent samples were characterized for pH, trace-metal levels, viscosity, specific gravity, mean aggregate particle size, and LPC (>1.0 rm) before and after depth (melt-blown polymeric media) filtration. The study showed that the use of a recycled fumed silica slurry (recycled five times) decreased the CMP removal rate and the coefficient of friction (COF) by 40%. A perfect relationship was observed between the removal rate and COF. It was concluded that the increase in mean aggregate particle size, which lowers the contact area between the abrasive particles and the wafer, had some impact on the removal rate data. In general, there is a stronger emphasis on slurry additives and chemical action in current CMP processing with much lower maximum defectivity performance specifications [2]. 

Adding the seed as slurry in the proper solvent composition is one of the best methods to control a batch cooled crystallizer. The slurry addition is started before reaching saturation and is continued until it can be determined that the seed is no longer dissolving. Although this method can increase the probability that seed will be present at the start of crystallization, the amount of seed actually remaining may be subject to excessive variation. 

For amorphous materials, sludges or other poor filtering products, improved filtration characteristics and/or filtrate clarity are enhanced with the use of filter aids. Slurry additives such as diatomaceous silica or perlite (pulverized rock), are employed to aid filtration. Diatomite is a sedimentary rock containing skeletons of unicellular plant organisms (diatoms). These... 

The lowest Cu concentrations were found in soil samples without pig slurry addition. The highest Cu concentrations in roots and shoots were found from plants grown in soil sampled at the end of the 5-year period of heavy pig slurry application (1996). In contrast, the effect of pig slurry application on plant uptake of Zn was not clear. 

Mixing of this first component with the dried precursor (1/1 by weight the preferred ratio) in an aqueous slurry, addition of phosphoric acid, boron and aluminum salts as promoters, followed by comminution in a balhnill and spray drying of the slurry... 

Figure 3.1 Selected examples of typical reaction pathways through which chemically promoted CMP of a metal (M) could operate. The slurry additives partidpating in these reactions are indicated in the box. A typical group of CMP-specific surface complexes is considered using the notations, (MCj (insoluble), MC (soluble), and MC j (partially soluble).

The corrosion-like electrochemical process of material removal refers to spatially uniform general corrosion of the metal surface. However, the wet CMP environment can also support certain other types of undesirable electrochemical corrosions, such as localized pitting, and bimetallic/galvanic decomposition that contribute to surface defects. The considerations for mitigating these defects constitute a major aspect of slurry (additive) selection, which in turn can be facilitated by the use of electrochemical techniques. 

CV shares essentially the same working principle with LSV, but the CV scans are repeated in triangular sweeps in both anodic and cathodic directions. Irreversible electrochemical reactions are readily detected in CV. Voltage sweep rate-dependent current features and scan-direction activated hysteresis of voltammograms serve as a useful metric for CV-based evaluations of slurry additives (Emery et al., 2005). The OCP (or oc) of a metal—solution interface has the same physical meaning as Ecorr for that system. While Econ is measured in the potentiodynamic mode, oc is generally determined in the potentiostatic mode as a function of time. The different nomenclatures are commonly used in view of these different methods used to measure the two parameters. 

America, W.G., Babu, S.V., 2004. Slurry additive effects on the suppression of silicon nitride removal during CMP. Electrochem. Solid-State Lett. 7 (12), G327—G330. 

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