Implementation and monitoring thermomechanical tests in a salt formation of a French potash mine

Gases encountered in different salt beds from evacuated and packer-sealed borehole sections in a potash mine were sampled and characterized for their chemical and isotopic composition so as to conclude on their origin and evolution in the salt rocks.These gases were either generated autochthonally or originate from fluid influx from the surrounding rocks outside the salt formation. Fixation in the salt rocks can take place laminar on mineral grain boundaries, disrupter and fracture zones or trapped in inclusions inside or between mineral grains.In situ flow tests with pure argon between several boreholes at distances ranging from decimeter to meter suggest that formation gas is stripped from the intermediate salt packet. This gas must have been trapped on grain boundaries along the pathways of the flowing argon.The stripped formation gas comprises mainly CO2 with traces of CH4 and H2. The CO2 isotopic composition matches well with gases originating from a mantle source, whereas CH4 is classified to be of thermogenic origin formed in a marine environment. Plausible explanations for the H2 generation are the radiolysis of water, reaction of FeII with water or microbial processes.We conclude that these trapped gases are of allochthonous origin migrating from the surrounding rocks into the salt formation where they were fixated mainly along fracture surfaces and fissures.

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UNDERGROUND APPLICATIONS OF SEISMIC MEASUREMENTS IN A SASKATCHEWAN POTASH MINE

Geophysics ◽

10.1190/1.1440061 ◽

1969 ◽

Vol 34 (6) ◽

pp. 906-915 ◽

Cited By ~ 2

Author(s):

D. J. Gendzwill

Keyword(s):

Seismic Refraction ◽

Salt Formation ◽

Mine Shaft ◽

Relative Time ◽

Refraction Method ◽

Seismic Records ◽

Underground Workings ◽

Seismic Refraction Method ◽

Potash Mine ◽

Seismic Measurements

The seismic refraction method is used underground in a Saskatchewan potash mine to monitor the thickness of the salt formation over the mine. Frequencies over 100 Hz characterize the seismic records. Mining machines create noise problems. Records are picked with 0.1 ms precision and a computer used to make the calculations. The statistical random error in the interpretation ranges from ±4 ft to ±15 ft for typical thicknesses of about 130 ft. Seismic techniques have aided in locating a nearly completed mine shaft with respect to existing underground workings. The geophysical work was originally intended as a verification and check against gross errors in the conventional surveying. Preliminary tests showed that the method would work with acceptable accuracy. Interpretation was made using only the relative time differences between geophones. The predicted position of the shaft center was 340±2 ft northeast and 235±10 ft northwest of a reference point. This compares with the actual position of 342.4 ft northeast and 228.5 ft northwest of the reference position determined upon completion of the shaft connection.

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Performance Evaluation of Heading-and-Winning Machines in the Conditions of Potash Mines

Applied Sciences ◽

10.3390/app11083444 ◽

2021 ◽

Vol 11 (8) ◽

pp. 3444

Author(s):

Sergey A. Lavrenko ◽

Dmitriy I. Shishlyannikov

Keyword(s):

Energy Efficiency ◽

Experimental Studies ◽

Efficiency Coefficient ◽

Mechanized Method ◽

Methodological Approaches ◽

The Stability ◽

Technical Solutions ◽

Potash Mine ◽

Complex Indicators ◽

Potassium Magnesium

The authors focus on the process of potash ore production by a mechanized method. They show that currently there are no approved procedures for assessing the performance of heading-and-winning machines operating in the conditions of potash mines. This causes difficulties in determining the field of application of heading-and-winning machines, complicates the search for implicit technical solutions for the modernisation of existing models of mining units, prohibits real-time monitoring of the stability of stope-based technological processes and makes it difficult to assess the performance of the services concerning mining enterprises. The work represents an aggregate assessment of the performance of heading-and-winning machines for potash mines by determining complex indicators describing the technological and technical levels of organising the work in stopes. Such indicators are the coefficients of productivity and energy efficiency, respectively. Experimental studies have been carried out in the conditions of the potash mine of the Verkhnekamskoye potassium-magnesium salt deposit to assess the performance of the latest and most productive Ural-20R heading-and-winning machines manufactured in Russia. Using the above methodological approaches, this paper shows that the unsatisfactory technological performance of the studied machine is due to the low productivity of the mine district transport. The average productivity coefficient was 0.29. At the same time, high values of the energy efficiency coefficient show that the productivity of the machine is on par with design conditions.

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