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Phosphate Matrix Pipeline Design Data and Tools for Efficiency Improvement

04-037-078Final

Introduction

Mining of phosphate is one of the major industries in Florida which produces some 30% of the world requirements. Drag-lines are used to remove the matrix from the ground after which it is transported as a water phosphate slurry by pipeline to the processing plant. The nominal diameters of the pipelines used in practice are 16, 18 and 20 inches in diameter and the pipelines are up to 8 miles in length.

It will be realized that the power consumption of one such line, 10 miles in length and 18 inches in diameter, in which phosphate is being pumped at a concentration of 50% by weight, is likely to be in the region of 11,500 H.P. (8.6 MW). Clearly, with power consumptions of this order it is essential that reliable operation should be sought at the minimum specific energy attainable.

It was for this reason and because of the variability of the size distribution, associated with the phosphate matrix material, that the Florida Institute of Phosphate Research commissioned the Georgia Iron Works Company and the unique capabilities of the GIW Hydraulic Test Laboratory to undertake a study into the flow characteristics of phosphate slurries as outlined in Appendix I.

The proposal entitled “Phosphate Matrix Pipeline Design Data and Tools for Efficiency Improvement” therefore, originated out of a desire to improve the efficiency and reliability of matrix slurry pipelines and at the same time provide the data and tools to help the practicing Florida Phosphate Mine Engineer carry out this work.

The overall objective of this proposal was therefore to assemble a comprehensive set of data on the full size pipeline and pump performance of phosphate matrix slurry and put it in a form suitable for Florida phosphate matrix designers, to make it possible for them to improve the efficiency of new and present systems.

Specifically this was to be achieved by carrying out a series of tests in both the laboratory and the field at different conditions on selected phosphate matrix samples and by analysis and correlation of the data into easily used forms.

The matrix to be tested and analyzed was to be identified and selected by a geological survey for its type and pumpability so that the tests and later results best cover a fully representative range of Florida matrix transport conditions. Three matrix samples were to be used. The pipelines employed in the test would be full size 16″, 18″ and 20″ diameter and the pumps would also be full size units now used in the field.

The data collected was to be pipeline head loss, slurry deposit velocity, pump head loss and pump efficiency at transport concentrations now pumped and higher in the different pipeline diameters noted earlier over a full range of velocities.

The correlated data presentation forms were to be designed to maximize the benefit to all levels of engineering users. It was intended that the data would be made available as raw tabulated data, pipe friction plots, algebraic relationships and in an easy to use menu driven computer program tool for use on a PC computer. It was expected that the computer program would include an energy analysis for a complete system, pump selection, pump spacing and startup sequence recommendation capabilities.

Related Publication:

FIPR Publication No. 04-037-079
Pipeline and Pump Evaluation and Selection Proqram (PAPES). Program Manual. Issue Version 1. GIW Testing Laboratory. September, 1989.