Mining Process

MINERAL RAW MATERIALS

The journey of metals from ground to surface

Mineral raw materials play a vital role in various sectors of the economy, including infrastructure, energy, manufacturing, medicine, aerospace engineering, telecommunications, and the pharmaceutical industry.

Mining involves excavations for extracting valuable mineral resources, a complex yet interesting process. It comprises different stages, including:

  • exploration and the evaluation of mineral resources
  • construction and operation of mining structures
  • extracting metal ores from the earth’s crust, using best sustainable practices and new technologies
  • transporting and processing metals to produce the final product
  • safely storing and managing tailings and other mining sub-products

 

Use this 3D map for a virtual tour of the mining process 

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CONTROLS

THE STAGES OF THE MINING PROCESS

Detailed overview of each stage

01.

Extraction

This stage involves extracting metals from ores found in the earth's crust. Extraction is practiced by: drilling, controlled blasting, ventilation, ore transportation, and support. At the Kassandra Mines we have identified a polymetallic replacement deposit. This means that it contains other metals too, including:

  • arsenopyrite (gold)

  • chalcopyrite (copper)

  • galena (lead, silver)

  • sphalerite (zinc)

02.

Crushing

The crushing stage involves the compression or impact of the ore against a rigid surface to reduce it into smaller pieces, which are then taken for grinding. Crushing is carried out inside crushers and runs through 3 stages: primary, secondary and tertiary crushing

03.

Grinding

Grinding is the process that removes unwanted material trapped in ores using the mechanical force of attrition. During this stage, crushed material is inserted in the mill along with water to liberate minerals trapped in the ores. Steel balls inside the mill help ground the ore even finer.

04.

Flotation

This stage involves separating minerals from their rock (waste materials) and classifying them into individual concentrates (metals without impurities).

Flotation takes place in 3 distinct circuits (containers) following specific sequence. At each stage, metal concentrates are extracted to the surface using water and special reagents.

05.

Dewatering

During the dewatering process, concentrates and tailings are passed through thickeners and high-pressure filter presses. This process effectively removes the significant quantities of water initially added during grinding and floating. The water is then recycled, and the concentrates and tailings have reduced moisture that facilitate road and sea transport. Specifically, the concentrates can travel in bulk form or jumbo bags.

06.

Backfilling Plant

After the production process is complete, the tailings generated from flotation and subsequent water removal are repurposed in two ways:

  1. They are conveyed to the backfilling plant where they are treated to produce a paste that is used to fill mined out areas.
  2. A small proportion of the tailings not treated as a backfill, are conveyed to the Kokkinolakkas Tailings Management Facility where they are safely stored as solids.
07.

Quality Control Laboratory

The Quality Control Laboratory conducts daily tests on samples and identifies metal concentrations. These tests are conducted throughout the production cycle, from exploration to flotation and the sale of the concentrates, to ensure that stringent standards are met across the mining cycle.

08.

Loading – Exports

The concentrated form achieved through enrichment is commonly referred to as concentrate. The lead-silver, zinc and gold concentrates are transported with tracks either to the port of Thessaloniki for export to the markets of southeastern Asia, Africa and Latin America, or to the port facilities at Stratoni to be loaded on ships for export to European destinations.

OPERATIONS

Minerals, the raw materials of our life

Gold, copper, silver, lead, and zinc minerals have brought and continue to bring substantial benefits to society and civilization. Thanks to their multiple properties and uses, they are integral to our national economy and development.

Find out more about Minerals & Metals