Backfilling sands

Backfilling sand is used in making hydraulically placed fill – a mixture of sand and water to fill voids created by underground mining. This has over the last few decades been the most popular form of underground mining backfill. Proven backfill sand deposits are situated mainly in areas of intense underground mining, especially those of hard coal and copper mining in the Upper Silesian Coal Basin and Legnica-Głogów Copper District. One of the major requirements which sand deposits should meet to be classified as backfill sand deposits is location in distance less than 50 km from the place where the raw material is to be used.

The majority of backfilling sand deposits are situated around the Upper Silesian Coal Basin. Three main deposit areas are differentiated: eastern, western and northern. The eastern area which is the center of production of that raw material extends from Kuźnica Warężyńska through the Pustynia Błędowska Desert as far as the vicinities of Jaworzno. It is characterized by occurrence of sands of fluvioglacial and locally eolian origin attaining up to 70 m in maximum thickness in the Pustynia Błędowska Desert. The second area with the largest resources comprises the Pleistocene valley of the Odra River in a part of the Racibórz Basin and western part of the Silesian Upland and its sand deposits are 15 to 20 m thick at the average. The northern area comprises the Mała Panew River valley with its sand deposits up to 40 m in thickness. The deposits are well explored but still undeveloped. Sandy-gravel deposits up to 40 m in thickness also occur in copper mining areas in the vicinities of Lubin.

The currently exploited backfilling sand deposits with the largest resources include Pustynia Błędowska – blok IV, Kotlarnia pole północne, Siersza-Misiury, Obora and Szczakowa pole I deposits.

Clastic rock raw materials occurence in Poland (inlcuding backfilling sand) is presented on the map.

The table given below shows resources and the current state of exploration and development of backfilling sand deposits.

Table 1. Backfilling sand - million m³

In 2012, anticipated economic resources of backfilling sand totaled 2,631 million m³ (or about 4,473 million tonnes (as recalculated using weight-to-volume ratio 1.7 t/ m³). Resources decreased by 2 million m³ due to the exploitation and losses.

In 2012, production of backfilling sand totaled 3,762 thousand m³ being 643 thousand m³ smaller than in the previous year. It was the fifth consecutive year of the declining production.

The figure given below shows changes in domestic resources and production of backfilling sands in Poland in the years 1989-2012.

Table 2. List of backfilling sands deposits - thousand m³

Prepared by: Agnieszka Malon