The November 2014 preliminary economic assessment for Claim Post's Seymourville silica sand project describes a seasonal wash plant, a year-round dry plant, 70% sand recovery and 500,000 t/y of 99.5% silica frac sand in four sizes.
Seymourville is a frac sand project in Manitoba, Canada, at latitude 51°09'58" N and longitude 96°19'56" W. P&E Mining Consultants prepared the Technical Report and Preliminary Economic Assessment (PEA) for Claim Post Resources Inc., with an effective date of November 1, 2014. Process selection is based on test data interpretation and conclusions by SGS and Consultec Engineering Services. The wash plant design follows the Phase Three test work flowsheet, with hydroseparation for primary classification, attrition scrubbing and then hydroseparation for desliming. Based on test work to date, and for the purpose of the design criteria, sand recovery to the product stream is taken as 70%, which the report calls a conservative assessment that further test work is expected to improve.
Critical Data
| Parameter | Value | Unit | Notes |
|---|---|---|---|
| Phase I plant throughput | 717,142 | t/y | Claim Post |
| Frac sand product | 502,000 | t/y | About 500,000 t/y |
| Frac sand recovery | 70 | % | Test work, conservative |
| Head grade | 95.7 | % SiO2 | SGS |
| Product grade | 99.5 | % SiO2 | SGS |
| Wet plant days | 180 | days per year | Warm weather months |
| Dry plant days | 300 | days per year | Stoppable for road limits |
| Wet plant throughput | 184 | t/h | 90% availability |
| Dry plant throughput | 87 | t/h | 80% availability |
| Hydroseparators | 4 | 3 m x 6 m | Two rougher and two cleaner |
| Attrition scrubbers | 4 | cells in series | 150 kW each, 30 minutes retention |
| Rejects thickener | 17 | m diameter | Outotec |
| Rotary dryer | 3 x 13 | m | 125 kW drive, propane fired |
| Product screens | 2 | Quad Deck | Four separate products |
| Bulk storage building | 250,000 | t | Plus six 600 t silos |
| Reagents | None | Not applicable | No reagents required in process |
Overview
A mobile pump station receives sand from the quarry and sends it by HDPE pipe to the wash plant. The quarry and wet plant operate during warm months only, but they are sized to support year-round operation of the dry plant. In the wet plant, rougher hydroseparation classifies the sand, attrition scrubbing liberates impurities that generally occur as surface coatings, and a second hydroseparation stage deslimes to produce a clean proppant. The cleaner hydrosizer product is dewatered on a belt filter and stored. The dry plant dries it, screens it into four sizes and loads trucks.
Key Process Stages
Reclaim system
The mobile pump station has a sump, crane, trash screen and pumping system. The sump is supplied with water by gravity and with sand from a backhoe. Submersible agitator pumps, typically 50 kW Toyo units supported by a portable gantry crane, operate two at a time with one on standby. They discharge to a skid-mounted grizzly screen over a pump box and slurry pump, which sends slurry through HDPE pipe to the wash plant. The reclaim system is designed for 90% availability.
Wet plant
The wet plant uses rougher hydroseparation for primary classification. Two hydroseparators operate in parallel for the rougher duty and two for the cleaner duty, each nominally 3 m in diameter and 6 m high, with feed density controlled by a dewatering hydrocyclone. Sizing is based on SGS test data and recommendations from McLanahan. Attrition scrubbers from Westpro give 30 minutes of high-intensity stirring retention in four cells in series, each with a 150 kW drive. The aim is to polish mineral surfaces and remove scale without comminution or breakage. The report recommends further test work on slurry density, power input and retention time. The cleaner hydrosizer product is dewatered on a belt filter and stored in a building of 250,000 t capacity with a reclaim system to feed the dry plant.
Rejects thickener
A 17 m diameter Outotec thickener with a steep conical bottom, a slope of about 20 degrees, is selected based on the very high settling velocity and terminal density of the rejects. It is sized for Phase I and II rejects. Overflow goes to the process water tank, and underflow slurry is stored in the plant rejects containment area developed as part of the quarry operation.
Dry plant
The dry plant takes product from the bulk storage building and dries it in a 3 m by 13 m Louisville Dryer rotary dryer with a 125 kW variable speed drive and a liquid propane burner. The dried product passes two Rotex Quad Deck screens that make four separate products, conveyed to four loadout hoppers equipped to charge and weigh highway haulage trucks. Finished product is held in the 250,000 t storage building or in one of six 600 t silos. For Phase II, the burner and fan will need upgrading, but the dryer is sized for the larger throughput.
Additional Interesting Data and Summary
The dry plant is configured so that operation can stop when road limits are in effect, while total annual throughput can still be achieved in a 300 day period. The Phase I rejects thickener and dryer are sized to handle Phase I and Phase II throughput without duplication.
The wash plant staffing table lists a process manager, a general foreman, a plant metallurgist, a metallurgical technician, a clerk, four shift supervisors, four operation lead hands and 20 process operators, including reclaim, wet plant and dry plant operators.
The process design criteria were built from SGS metallurgical test data and mineralogy, studies by equipment suppliers and Claim Post's own experience, with Consultec's related knowledge applied. The criteria are intended to recover and ship approximately 500,000 t/y of frac sand, and equipment sizing and selection rest on test data and investigations by Consultec and selected outside experts.
Key Processes
- Slurry reclaim from the quarry by mobile pump station
- Rougher hydroseparation for classification
- Attrition scrubbing of sand grains
- Cleaner hydroseparation for desliming
- Belt filter dewatering and bulk storage
- Propane-fired rotary drying
- Four-size product screening and truck loadout
Source: Technical Report and Preliminary Economic Assessment on the Seymourville Silica Sand Project, Manitoba, Canada, November 1, 2014.
