It has been noted that the transportation of slurry is an attractive option when the geography of the gold deposit makes difficult to build a complete processing plant near the ore body. Then it is important to analyze the hydraulic transport of solids and then consider the economic and engineering aspects upon which construction and operation of such a line would be based. The pipeline can cover a short or long distance. Basically, the design and construction of pipelines for fluids such as crude oil are relatively simple when contrasted against the complex problems encountered in slurry systems. In this way, considerable effort must be done in hydraulic research in order to understand the variables and properties of the slurry. This attitude was reward and the design of slurry transport involves art, science and experience.
In order to reduce the risk factors in the construction and operation of large scale slurry systems, some studies are conducted in pilot scale test loops. The pilot scale project is designed to provide the basic engineering data necessary to design, slurry transport pipeline. Usually, three slurry solids concentrations are pumped at several line velocities and optimum slurry densities and velocities are determined. In this way, critical velocities, friction head losses, power requirements, and particle size are determined from measurements and calculations. Wear test are also strongly recommended and anticipated pipe wear rates are used in the design of materials.
Simplicity of construction and minimization of environment impact are important benefits of the pipeline system. The basic construction includes soil or gravel surfaced road with reasonable grades and large radius turns. The smooth surface of the road would provide access for any possible problem. Also, the design must include a corrosion protection system due to steel pipes are operating under several sources of corrosion. Any changes in feed material or the relocation of the slurry preparation facility may be accomplished with difficulty. Changes in annual throughput may also be a serious problem due to reduction in production may best be met by shutting down the line; increased capacity may be obtained by increased velocity. In either case, significant unit cost increases may be anticipated.
To perform a rheological testing program and hydraulic tests are important. The cost of both programs is small when compared with the total investment in a transport system. In a test program unanticipated problems tend to develop solutions to these problems. The data developed in a testing program may be employed to check the mathematical statements employed to design the final system and reduce the risk involve in the project.