We follow a strict productive process to guarantee an optimal results
In order to market any of our final products, at CAVISA we carry out a series of processes that we classify between processes in mine and processes in plant.
Mine work consists of the safe extraction and recovery of the ore, for which it is necessary to prepare the deposit. Tasks are carried out to clear, extract and collect the soil, open guard ditches, preparation of accesses and all the necessary tasks to recover the mineral safely accessible.
The ore is then extracted according to the needs of the market and therefore from our profit establishment plant, using one of the two types of work that we apply: Hydromining or traditional open pit mining.
Then, as needed, we proceed to start with the processes in our plant as such.
General flowchart
- Mine processes
- Roughing
Mine processes
We combine transfer mining with hydromining. The recovery of the minerals is carried out basically by two processes:
Dry way
It is the traditional mining method.
- Extraction: the ore is extracted by excavators. It consists of taking out the ore in benches of about 4 meters of power and about 6 meters wide.
- Loading, transporting, stacking: materials are sorted according to their nature, quality or destination:
- Waste rocks that will be transported by truck to storages to their restoration or to reuse in other applications, as refill old mines.
- Raw material ordered by qualities that will be transported by truck to the stockpiles in Winter Stock platform.
Wet way
Also called Hydromining or Hydraulic Mining, it is a less selective but effective method in clay soils and with a significant reduction in occupational risks by reducing the presence in short operators to maintenance tasks. It consists of starting remotely using hydraulic monitors, pumps and pipelines for the transport of the ore (in the form of pulp) to the plant. In our case the water comes from the site itself, from the rain, and is recirculated from the plant.
- Extraction: material is extracted using fresh water monitors recirculated from the plant and barbotine pumps that feed the roughing plant directly.
- Transport: is carried out by 6" anti-wear pipes, due to the high concentration of solids of the pulps.
Basic elements that form the Hydromining system are:
- Television Circuit: allows real-time control of the reservoir and the current water level that conditions the previous drainage time, the density of the pulp and the necessary water flow.
- Hydraulic monitor: used to disintegrate the materials of the slopes and homogenize the barbotine. The flow to be sent in the monitor depends on the density of pulp and the presence of storm water.
- Two types of pumping:
- In the initial phase, pumping for the withdrawal of clean water from the rain accumulated in the reservoir.
- Operating phase, pumping pulps with high solids content to feed the roughing stage directly.
The use of one or the other way type will depend on multiple factors such as distance to the reservoir, availability of water, knowledge of the resource, more or less selective process.
Plant processes
The processes in the plant depend on the product you want to obtain as main: kaolin, mica or sands.
Kaolin Processes
Roughing stage
The ore collected in the strategic winter stock or from the hydromine, is fed to the plant where it is first roughed. These are several phases of wet roughing of minerals from both stocks and mines, in which tailings and thick by-products are removed.
In various processes of Roughing it is about getting to separate as best as possible these 3 base minerals of our production: Kaolin, Micas and Sands; being the subsequent processes aimed at reducing water and moisture in them to convert them into marketable products.
Refining stage
Kaolin refined by continuous hydrocyclone stages is collected in hoppers and sent by pumps to the next phase. Tailings generated in this refining phase are composed of by-products that are accumulated in old mines for future use, or for definitive environmental restoration.
Thickened stage
Kaolin will remain for a minimum time at this stage to increase the density and in parallel recover excess waters for the previous roughing stage.
Homogeneization
Chemical parameters of production prior to the filtration stages are analyzed and corrected. It seeks to optimize the use of raw materials while maintaining the specifications of each natural product as stable as possible.
Filtrated and extrusioned
Using 3 huge press filters, kaolin cakes are formed where the moisture content can be reduced to 27%. The extruder and stripper transform the cakes into pellets for later drying.
Drying stage
Produced by hot air generated by the vein-type air burner that consumes LNG. Consists in perforated stainless steel trays, linked together, on which the kaolin pellets are fed. In general, two presentations occur: dry (<1% H) and wet (around 10% H).
Intermedy kaolin stocks
Bulk kaolins are colleted to the bulk warehouse where stockpiles are identified by signage with product name. Dry kaolins are colleted either in silos or in big bag with their corresponding identification label, with allows us to trace their characteristics with product data sheet.
Powder caolin
Characteristics requested by the powdered product customer are achieved with a soft grinding stage and classification, not varying the physical or chemical characteristics.
Palletized
Final product can be marketed in different presentations: Bulk bags of 1 t, paper bags, plastic bags. Bulk bags produced will carry a label containing: product type, number, production date, operator and weight of the bag, related to the number of final pallet and ensuring traceability at all times.
Expedition
Most common services of our products are: sale EXW CAVISA, CIF destination port, or DDP Customer facilities. Once the packing list is generated, it is related to the numbered pallets that conform the order and which in turn are related to the bulk bags and intermediate stocks that make up the batch produced, ensuring traceability.
Mica Processes
Feeder
For the production of micas, as in the case of kaolin we can use the Winter Stock or feed directly from the Hydromine by wet way.
Flotation
Mineralurgic process by which we can get the separation of mica from other minerals. It is a process linked to the kaolin in order to produce mica has to be in place the roughing and refining section of the kaolin production process. A conditioning of the sands will be carried out in the feed to ensure the effectiveness of the flotation where necessary reagents are incorporated. Two cascading flotations are produced for a good recovery.
Thickened stage
Floating mica from the second flotation is sent to a thickening tank whose overflow waters are collected and directed back to the feed of the flotation stage reducing water and reagent consumption.
Filtrated and drying
Mica pulps are filtered into a rotary vacuum filter that feeds an LNG-fed rotary dryer. From here you get mica “madre”, which can be marketed directly or go through various processes of sieving or grinding, depending on the use that is needed.
Sieving
Various fractions are generated according to the needs of the market.
Grinding and micronizing
To cover the needs of the markets we generate both delaminated micas and micronized micas. For this purpose, a mill based on autogenous grinding is mainly used, where the material itself is microned by shock and/or friction generated by the compressed air currents injected into the grinding chamber.
Labeling
Each pallet is identified with a numbered label containing the product name, pallet weight, lot number, operator and date, and which is related to the collection or bulk bags that form the batch used for processing, ensuring the traceability of each product at all times.
Palletized
Can be made in bulk bags, small bags of paper or plastic on pallet. Bulk bags produced will carry a label containing: product type, Big Bag number, production date, operator and bag weight. Pallets are usually made at 1200 kgs.
Expedition
The most common services of our products are: sale EXW Cavisa, CIF destination port, or DDP Customer facilities. Once the packing list is generated, it is related to the numbered pallets that form the order and which in turn are related to the big bags and intermediate stocks that make up the batch produced, ensuring traceability.
Sands Processes
"Arena montaña"
In Sands Treatment and Recovery Plant we mainly treat the Mountain Sand, accumulated over years and other aggregates from our mines. They are unwashed sands, with presence of wastes rocks and micas, approximately size 0 -10 mm used by many promoters for environmental regenerations, beaches and soil reconstruction.
Washing stage
Washing is a slow process in which using water from the mine itself we carefully separate and recover on one side the silica sands and on the other the finest materials with other mineralogies and uses.
Classification
These sands are generally rounded by not proceeding from crushing and grinding processes so their uses are indicated according to granulometries; therefore we classify the different granulometries suitable for its final use: animal welfare, environmental regenerations, fillings, quartz gravel.
Grinding stage
One of the previously washed and classified fractions, consisting of silica sands is milled to offer the market the right granulometric curve for the manufacture of concretes. The ground sand 0-5 is characterized by the presence of fine of good quality.
Storage
Thicker fractions are stored in outdoor or indoor stockpiles, taking special care in the storage of our finest fractions dedicated to Animal Welfare.
