The requirements for separating materials with different densities are becoming more demanding, and regardless of whether it comes to the purity of the separated materials, the machine’s performance, or adherence to environmental standards that guarantee a sustainable process – Allgaier delivers the right answer with its newest development: the GSort Densimetric Table.

The GSort’s density separation process is based on a tilted, vibrating deck, making it possible to adjust parameters individually, quickly, and easily, ensuring that the machine is always perfectly tuned for the materials being separated.

CASES WITH DIFFERENT MATERIALS

When we have the desired particle liberation, we can obtain the proper quality. This quality is defined by the minerals market, being a good example the mineral Baryte.

Worldwide, around 70% of baryte is used as a weighting agent for drilling fluids in oil and gas exploration to suppress high formation pressures and prevent blowouts.

For the oil industry the absolute density in Baryte required is around 4,2 kg/ltr – Baryte’s density in its purest form is 4,5 kg/ltr. For some Chemical applications it can come up to 4,35 kg/ltr.

FIRST TESTS PERFORMED ON BARYTE WITH DENSIMETRIC TABLES

Between the end of 2014 and the beginning of 2015, we carried out several tests with 80 tons of Baryte approx., from three different mines located in Morocco and China. For this first round of tests, performed at our test center previously located in Asturias, Spain, we used our pilot test plant adapted to local real conditions. The target density of Baryte after concentration was 4,2 kg/ltr and with the tests we reached 4,44 kg/ltr in one fraction.

Following tests were performed in 2017 using an old Densimetric Table sold as a “try and buy” version. In this scenario, the target density of Baryte after concentration was 4,2 kg/ltr and we obtained 4,32 kg/ltr with a sample of 30 t/h of testing material. un flujo de alimentación de 30 t / h de material.

TESTS FOR MINING APPLICATIONS USING THE GSort DENSIMETRIC TABLE

Potential application: Iron ore concentration with an approximate production per year of 2.300.000 Tons.

During the development stages of the GSort, iron pellets and rocks were used as contaminant agents during the tests performed for iron ore.

The main iron-based ores used were Magnetite (Fe3 O4, 72% iron), and Hematite (Fe2O3, 70% iron).

The Magnetite process requires:

- Coarse particles direct to autogenous mill + screen

- Magnetic separation

- Wet process with mills and hydro-cyclones, following a metallurgical process

The Hematite process requires:

- Multistage crushing + screening process to obtain i.e. 1 – 10 mm fraction.

- Concentration process based on hydro-classificators. Here the GSort can be introduced for a separation with dry density concentration, and energy and water savings.

The typical iron concentration after crushing and screening is of 55%, while the target concentration after size reduction ranges from 55% to 60 -67% range

For an increased performance in Magnetite and Hematite processes, there are two alternatives:

Flotation cells (Hydrosizing):

In this wet process the water drags light particles - usually fine to medium size rocks and some fine iron - leaving coarse rocks and medium to coarse iron at the bottom outlet.

Dry Densimetric Concentration with the GSort.

The Gsort dry densimetric separation process is achieved on a vibrating, inclined base. A flow of rising air crosses this base and has two effects on the material. Less dense products float without touching the base and slide to the lower portion of the inclined table. More dense product contacts the table and is pushed towards the top due to the vibration. The greater the difference in density of the products, the larger the grain size bands can be.

In some metallic mining process, the metallic fraction is combined with other grain elements - usually sulphates -, thus the metallic fraction is not homogeneously dissolved on the rock. In these processes it is possible to use the GSort.

The greater the difference in density between the products, the larger the grain size bands can become. With the GSort it is possible to adjust parameters individually, quickly and easily, ensuring that the machine is always perfectly adjusted for the materials being separated.

An extraction hood and ducts can be installed to partially or fully recirculate the air.

USE OF THE GSort IN OTHER MINING PROCESSES

Dry density separation offers outstanding advantages in water and energy saving and is more environmentally friendly than conventional wet processes.

Advantages in using the GSort as alternative to wet processes include:

• Suitable in processes where crushing and screening are applied to liberate the mineral.

• Size range 1 to 50 mm (even 0,5 to 80 mm, depending of density) can be concentrated with GSORT

 • Minimum difference in absolute density between heavy fraction and light fraction of about 20%.

This compact solution is also available to be installed in underground mines. Some potential customers recommendation advises on concentrating the reject on the pit. Every ton left down means:

- Less energy is required to move up the surface.

- Lower transportation costs.

- Lower process flow (washing, crushing, drying…)

GSort DENSITY SEPARATION – NEW OPPORTUNITIES BY AIR SEPARATION

The new GSort can replace or complement wet gravity separators. This not only improves water management, but also reduces energy costs. Moreover, the new design lowers assembly, disassembly, and transportation costs.

The GSORT also can be combined with sensor technologies, as our MSort.

Sorting parameters can be adjusted individually offering maximum flexibility. The machine’s overall height has been reduced for an optimized equipment footprint.

The new design minimizes downtimes and guarantees stable performance.