Pivoted Weigh Screw System for Alumina Dosing
A purpose-designed pivoted weigh screw conveyor package delivering accurate gravimetric dosing of alumina for a major new processing facility in Gladstone, Queensland.
Problem
Our client, a Queensland-based provider of bulk materials handling, filtration and processing solutions required a purpose-designed weighing and feeding solution for a major alumina processing facility in Gladstone, Queensland.
The project required accurate dosing of alumina within the green fields process stream. The weighing system needed to be installed downstream of the alumina silo agitator, live bottom bin feeder and screw conveyor, it weighs and delivers into an inclined screw conveyor feeding a bucket elevator.
The system needed to achieve a required throughput of 30 t/hr while providing consistent and reliable gravimetric measurement prior to the material entering the plant’s mixing tanks.
Solution
Given the client’s project requirements, we designed, manufactured and supplied a ModQuip Pivoted Weigh Screw conveyor package to provide continuous weighing and controlled feeding of alumina through the process.
The supplied package included:
- Pivoted weigh screw conveyor
- Integrated control cabinet
- Custom support frame
- Load cell weighing system
Following detailed engineering calculations and screw conveyor sizing assessments, the system was designed for a required throughput of 30 t/hr, with an inlet-to-outlet centreline length of 2,490 mm.
A lower operating speed was selected to support gravimetric weighing accuracy by maintaining a stable and consistent material bed depth within the screw conveyor.
To meet the product purity requirements of the application, the screw conveyor and control cabinet were manufactured from stainless steel. The structural support frame was fabricated from mild steel with a powder-coated finish and remained isolated from direct product contact.
The ModQuip Pivot Weigh Screw provides continuous measurement of bulk material as it is conveyed, allowing the flow of alumina to be accurately monitored and controlled within the process.
Outcome
The completed system provided a purpose-designed gravimetric weighing and conveying solution capable of meeting the required 30 t/hr alumina throughput.
The final design provided a calculated conveying capacity of approximately 31.5 t/hr, while the controlled 70 RPM operating speed supported stable material flow for accurate weighing and feed control.
The stainless-steel construction addressed the product purity requirements of the application while providing a durable solution for the processing environment.
Following design approval and sign-off, manufacturing commenced in late January 2026. Factory acceptance testing and delivery to Queensland were successfully completed in mid-June 2026.
