Guar gum needs to be thin enough to make it easier to pump. Then as it flows down the pipe, the fluid needs to gel up to support the proppant and flush it deep into the fractures. After that process, the gel has to break down so we can flow back and recover the fracking fluid, but leave the proppant behind. This requires a chemical process which produces then breaks the gel cross-linking at a predictable rate. Guar+boron+proprietary chemicals can accomplish both of these goals at once. Guar gum retards ice crystal growth nonspecifically by slowing mass transfer across the solid/liquid interface.
Hydrochloric acid water. Hydrogen chloride can be generated in many ways, and thus several precursors to hydrochloric acid exist. The large-scale production of hydrochloric acid is almost always integrated with the industrial scale production of other chemicals. Hydrochloric acid is produced in solutions up to 38% HCl (concentrated grade). Higher concentrations up to just over 40% are chemically possible, but the evaporation rate is then so high that storage and handling require extra precautions, such as pressurization and cooling. Bulk industrial-grade is therefore 30% to 35%, optimized to balance transport efficiency and product loss through evaporation. In the United States, solutions of