CASE STUDY | Aggregate Quality Control

ROCKLABS supply sample preparation equipment to mining clients, commercial laboratories, and research institutions. The equipment includes crushers, pulverizers, and sample dividers for the mining of gold, silver, platinum, and palladium. They also create custom solutions.


ROCKLAB’s client operates a large aggregate quarry in Europe. The output of the quarry was restricted because of the time involved in manually performing quality control checks on the crushed material.

The crushed material needs to be sampled and tested regularly to ensure it meets requirements for the grades of aggregate size and amount of ‘fines’. (Fines are particles that are too small to be useful and are discarded when the aggregate is washed).

A typical crushed aggregate batch will contain a range of crushed particle sizes and some ‘fines’. The quality control procedure establishes how much of the batch is outside the target range of particle sizes, the proportion of various target particle sizes, and the amount of ‘fines’.

To increase the quality control throughput, ROCKLAB’s client proposed an automated sampling and testing system.

  • Design, build, test, install and commission an automated system
  • Novel solutions required to automate many processes which are constrained by the EN932-1 standard and have traditionally been carried out manually:
    • Drying sample before testing
    • Handling and storing standard laboratory sieves, which are stacked together on a sieve shaker for particle size testing
    • Fines wash, where a sample is weighed, rinsed until clear of fines, dried then weighed again
    • Drying of fines wash sieves
    • Cleaning of sieves after each test batch
    • Inspection of sieves
  • The solution proposed by ROCKLABS was an enclosed area comprised of individual stations (machines in their own right) and multi-axis robots to move samples and sieves between them.
  • Some of the stations were based on equipment ROCKLABS has designed before, including the sample infeed, proportional splitting, sample weighing, and outfeed.
  • Many of the stations had no prior existing solution, so had to be designed from scratch, including the: robot end effector to grip and manipulate sieves and sample bins; fines wash; sample drying; sieve cleaning, inspection, and drying; automatic clamping of sieves onto shaker; and sieve stacking.
  • Our Caliber Design engineer was responsible for the Sieve cleaning and Robot end effector (Gripper) ‘stations’. These were designed from scratch and involved:
    • brainstorming
    • testing (of existing, manual methods against prototypes of the brainstormed methods)
    • reviews
    • detail design
    • discussion with suppliers
    • collaboration with the Client’s design team to integrate these stations into the overall project
    • drawings
    • creating purchasing BOMs
    • supporting the fitters in the workshop to build and test
Caliber’s project-based resource enabled ROCKLABS to keep the design of their project on schedule; it enabled them to scale their resource up and down to suit their client’s requirements and ensure they met their design deadlines.

To every job, our engineers bring a culture of starting from first principles, researching, prototyping, and testing. Onsite at ROCKLABS, our engineer delivered complete and on-time design solutions for the Sieve Cleaning and Gripper. He also provided support to the workshop and other design engineers during testing, manufacture, and assembly.

Cavotech MoorMaster baseframe analysis

RoboPrep Automated Aggregate Analysis

Thanks again for all your help. It is hard finding people like yourself who you can just give a vague outline to and let them go away and start designing something that has a decent amount of thought around it.

Egan Bowden

Design Engineer, ROCKLABS

Sieve Cleaning Station

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