Rock Products

JUN 2019

Rock Products is the aggregates industry's leading source for market analysis and technology solutions, delivering critical content focusing on aggregates-processing equipment; operational efficiencies; management best practices; comprehensive market

Issue link:

Contents of this Issue


Page 36 of 91 ROCKproducts • June 2019 • 35 oversized material. This will show where bottlenecks may exist in the system and allow some of them to be designed out of the system before the plant is commissioned. 3. Plant Layout Most frac sand producers push their processing plants to the breaking point and then back off enough to prevent continuous breakdowns. Planning on the front end where the bottlenecks will most likely occur in the system will make future expansion more affordable while keeping initial costs in check. Site layout is the most critical part of this planning. It is much easier to replace a few pieces of equipment than to rearrange the entire system. Understanding where you are laying out your plant and how your stockpiles can drain can save you money and time in the future. Stockpiles can produce a good amount of water and if managed correctly can be reused for future processing. Getting bids for a higher feed rate than what is initially required may reveal that some equipment's capacity is doubled for as little as a 20% increase in price. Upsizing equipment and conveyors during the initial build can amount to significant savings when an expansion is added in the future. 4. Schedule Maintenance Downtime No one wants to shut down when everything is going right, but that is always the best time to. It is easy to get behind schedule and to put off maintenance until something goes wrong, but experience teaches us that this is always costlier and a less efficient use of time. An unplanned shutdown can mean hours of digging out con- veyors and equipment or replacing parts that were never meant to see wear. Planning equipment runtime based on manufacturer-estimated levels allows for scheduled mainte- nance so that wear parts are replaced rather than the steel body of equipment or beams from the structure. Analyzing wear patterns also gives insight into what parts will need to be replaced next. Long lead time items may then be ordered preemptively, reducing downtime and further improving system uptime. Unplanned shutdowns may still happen, but they are much less likely if proper care is taken of the system. 5. Consider All Tailings Management Options With the decline of water availability and rise of environmental concerns, the days of sending plant tailings to a pond without another thought are coming to a close. In some regions, we are well past that point. In others, we are only just beginning to consider it. Regardless of where you are, tailings management solutions have come a long way in the past 20 years and can now eliminate settling ponds with high efficiency and reliability. Many frac sand operations are adding fines recovery systems, thickeners and filter presses (or some combination of the three) to reduce costs and/or to produce a sellable product. It is prudent to consider these options during the initial plant design. A fines recovery system may significantly reduce the amount of fines sent to the pond. This can cut cleanout costs in half and may provide a sellable product as back fill or a newly popular 200 mesh frac sand, but these results vary based on the deposit, so testing is critical. The next step is to recover the process water and thicken the solids in the tailings to greatly reduce pond size and provide process water at the wash plant, saving horsepower on water pumps. The last stage is to take the thickened solids and press them into a cake. This allows for the complete elimination of set- tling ponds, opening up land for mining, eliminating costs of cleaning out those ponds and, sometimes, adding another sellable product. All Things Considered At the end of the day there are going to be many equipment options to consider when selecting your plant, but the princi- ples that will ensure you the highest return on investment are going to be the same. These five areas will help to ensure that your plant is successful long-term and will be able to meet changing demands throughout the life of your deposit. S Information for this article courtesy of McLanahan Corp. GeT Level Sensors on your Radar NCR-80 non-contact radar measures reliably in dusty cement, sand, and gravel. Measure silo inventory using 80 GHz frequency focused in a narrow 4° beam angle with accuracy of 0.2 inches. Get data from the BinView web app, Binventory software, or panel meter displays. 402-434-9102

Articles in this issue

Links on this page

Archives of this issue

view archives of Rock Products - JUN 2019