RAG has been producing hard coal by underground mining in Germany until the end of 2018 and continues to be responsible for the resulting consequences in North Rhine-Westphalia and Saarland. For almost 200 years, thousands of mine shafts and other cavities have been developed underground, many of them at a time when computers and 3D models were still unknown.

To protect near-surface drinking water reservoirs, mine water treatment is one of RAG’s most critical post-mining activities. Depending on the type of contamination of the mine water, several treatment steps are carried out. This application initially focuses on hydrogen sulfide (H2S) treatment.

At present, the exact composition of the mine water is checked at regular intervals by elaborate laboratory tests. As part of the test also the hydrogen sulfide content is determined. If too much hydrogen sulfide is measured, hydrogen peroxide (H2O2) is used as an additive in the treatment process to remove hydrogen sulfide from the mine water. The dosage of hydrogen peroxide is determined by the measured hydrogen sulfide content. The laboratory tests ensure a very accurate measurement of the hydrogen sulfide level, but only at a specific point in time. An adjustment of the hydrogen peroxide dosage is therefore only carried out with a delay and requires manual adjustments.

The aim of this use case is to dynamically adjust the dosing of the hydrogen peroxide in order to react more quickly to fluctuations in the hydrogen sulfide content and hereby ensure consistent quality of the treated water. A closed control loop for hydrogen sulfide measurement and H2O2 dosing shall be created. 

RAG can provide detailed data of a single pump & treatment facility for about 12 continuous months. It contains the following data points: amount of hydrogen sulfide in the raw water, volume of pumped water, dosage of H2O2, sulfur in the air after treatment and air temperature.   

At this point RAG considers it very unlikely to find a working forecasting model for the sulfur levels of its mine water. Therefore, a combined hardware & software solution to measure sulfur in a reliable, quick and affordable way seems the most promising approach. Nevertheless: Surprise us with your idea!

In case of a success test of your solution it is planned to extend it by additional treatment steps, to roll it out to further locations and to integrate it with the current infrastructure (Siemens S7) in a follow-up project. 

If you have applied and you want to participate at the Q&A - Session please register by clicking this Link.

• In-depth knowledge of IoT systems and sensor technology
• Experience in IoT software engineering
• Basic understanding of water management / water treatment is a plus
• Experience with process control systems, eg. Siemens S7 or WinCC is a plus

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• Faster, more dynamic adjustment of H2O2 dosing according to hydrogen sulfide (H2S) levels
• Continuous collection and transfer of sulfur measurements
• A combined hardware & software approach looks most promising to us
• The solution shall be easily expandable to manage all other mine water treatment steps in the future
• Graphical user interface

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The project can be divided into three milestones:

1. First milestone is reached, when existing data is integrated and analyzed, so that the correlation between amount of pumped water, hydrogen sulfide measurement and H2O2 dosing is precisely determent.

2. With the second milestone your solution significantly accelerations the adjustment of the H2O2 dosing according the sulfur levels. 

3. Third, your solution proofs its capabilities in an A/B test on premise.

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