Exploration and Mining
Neuburg Siliceous Earth is a globally unique raw material that was formed millions of years ago and is now used as a high-quality functional filler in many industries. It is a natural mineral blend of finest silica and kaolinite. HOFFMANN MINERAL is the only company that extracts and processes this resource.
How to find Neuburg Siliceous Earth?
In the early times of exploiting siliceous earth it was relatively simple to find out such deposits. The layers close to the surface became visible in the forests beneath the roots of tumbled trees, or they showed up during ploughing work on the fields. The long history of exploitation explains, however, that the siliceous earth deposits near the soil surface have been used up by now. The remaining deposits actually are mostly covered with clay and sand layers several meters in thickness, and this means the valuable raw material can only be identified by special procedures.
Geological Exploration
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First, potential sites are geologically surveyed.
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This is followed by drilling to determine the exact location and quality of the raw material beneath the earth's surface.
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Special drilling equipment with a diameter of approximately 15 cm and a depth of up to 80 meters is used in a grid pattern.
State of Exploration
Presently, siliceous earth deposits have been explored for about 30 years of direct usage. HOFFMANN MINERAL assumes that with reasonable use of the deposits without excessive increases, deposits are still at hand for more than 100 years.
Extraction in Open-Pit Mining
The extraction of Neuburg Siliceous Earth is an example of the successful interplay between science, technology, and environmental conservation.
The History of Extraction
Neuburg Siliceous Earth has been mined since Roman times, initially in small open-pit quarries. However, this method had disadvantages, such as water accumulation from rain and high land consumption. Over the past 200 years, mining shifted underground, utilizing vertical shafts and tunnels. Early extraction relied on simple tools like picks and carts. Later, modern equipment such as pneumatic drills and motorized transport systems were introduced, leading to the development of multi-level mines. Despite these advancements, large quantities of siliceous earth remained unused as they were required to serve as pillars and structural support for the mines.
Modern Extraction
Modern open-pit mining is currently the most efficient and safest extraction method. Large excavators and dump trucks allow for rapid movement of earth masses. Loose rock blasting is rarely required, used only to break down embedded boulders. In most cases, overburden from the opening of a new pit is directly backfilled into a nearby, already exhausted open-pit mine. This approach greatly minimizes the creation of waste heaps.
From Open-Pit Mining to Recultivation
The opening, backfilling, and reclamation of the "Am Steinbruch" open-pit mine are carried out by HOFFMANN MINERAL based on decades of experience and state-of-the-art technology. The open-pit mine was established in the 1990s following exploratory drilling and the necessary permits.
Starting in 1994, deforestation, archaeological surveys, and the removal of topsoil and overburden took place. The excavated material was used to backfill a neighboring open-pit mine.
The extraction of siliceous earth began in 1996 and continued until 2006, gradually deepening until the bottom of the pit reached 70 meters below the surface.
Beginning in 2008, the open-pit mine was backfilled and prepared for reclamation. In 2010, the area was planted and a wetland biotope was created, with additional areas set to be reclaimed at a later stage.
Sustainable & Long-Term
In this way, the unique Neuburg Siliceous Earth is responsibly extracted and made available for industrial applications.