Dewatering: Thickening, Filtering, CCD, Water Treatment & Tailings Disposal

Dewatering: Thickening, Filtering, CCD, Water Treatment & Tailings Disposal

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Monitoring and Remediation of Mining Waste (13 replies)

Oberfuhrer
8 years ago
Oberfuhrer 8 years ago

I’m working with supervision and remediation of mines and mine waste in Sweden and have come to the conclusion that even in a relatively small country like Sweden the demands on how to characterize and treat mine waste can differ. This made me curious on how other countries do this.

So what demands on characterizing mine waste are there from the government in your country?

Any specific tests that has to be done to gain insight on potential of AMD?

How is potential outflow of harmful elements decided? Specific tests?

Does this wary depending on the type of ore?

If anyone could answer these questions I would be glad. Also feel free to ask me or others about the subject will answer as soon as I can depend time available.

(unknown)
8 years ago
(unknown) 8 years ago

I would be glad to participate in the discussion but as you stated these requirements are varied depending on the deposit type, the extraction and processing methods, mitigation of impacts and what you are trying to protect.

Yesterday I was reviewing the prediction at a mine site that included mineralogy, quantitative micro mineralogy, Acid Base Accounting (ABA), modified SPLP, humidity cells tests on various wastes, evaluation of existing waste piles and evaluation of similar sites just to name a few. The proposed mine is in a protected area with endangered fish species.

The basis for the analysis is a risk assessment. Acid generation is only one of the indicators of the potential for adverse impacts.

Oberstorm
8 years ago
Oberstorm 8 years ago

Agreed, the local jurisdiction may have specific tests that must be performed by a certified laboratory, i.e. Nevada. Newmont generally uses net carbonate value worldwide, often in addition to tests required by the local jurisdiction.

Oberfuhrer
8 years ago
Oberfuhrer 8 years ago

In Sweden at the moment this is not regulated at all as far as I can see... So it is up to the monitors to make sure that enough tests are done and if the company and monitor disagree take it to court. I have seen permissions been granted without a thorough humidity cell test where the material has been show to be acid. And other times when according to me to few tests has been done.

Also here the recipient in question changes how much that need to be done for example I am hoping to be able to use the biotic legend model more here to see possible effects on some waters.

But what I think I find most interesting at the moment is how do you decide what tests that should be done? Sometimes the company do not agree with how many test or what tests that should be done. Is there any rule for this kind of stuff in your countries?

Oberstorm
8 years ago
Oberstorm 8 years ago

Refer to the GARD Guide http://www.gardguide.com

(unknown)
8 years ago
(unknown) 8 years ago

In Chile we are beginning a project to adapting the Gard Guide for the Chilean reality. One off the principal aims Isabel is to establish an iterative process for the life of mine.

(unknown)
8 years ago
(unknown) 8 years ago

In Australia, each state controls the environmental regulation so we have 7 different sets of regulations the AMD issues are treated fairly similarly. The Federal government has a series of leading practice Sustainable development guides.

Some of the books are under review at the moment. There is a wealth of information in the GARD Guide.

(unknown)
8 years ago
(unknown) 8 years ago

In Canada, MEND publications are the references for ARD/ML (AMD). The MEND website contains wealth of information and references covering nearly all aspect of AMD

(from characterization planning to management). These references are developed by a group of well known experts in the matter.

http://www.mend-nedem.org/Default-e.aspx

Oberfuhrer
8 years ago
Oberfuhrer 8 years ago

Thank you all for the response,

I try to use both MEND and the GARD Guide as much as I can. A big thank you to those who puts them together they are really helpful since it is not possible to keep all these things in memory.

However, what I am struggling with at the moment is a way to make sure that the appropriate tests are done before permits and accompanying terms of how to treat the main waste and amount of allowed pollution is delivered. Partly an economical question but if that is set aside. I guess it all more or less boils down to having personnel that is well enough educated about the problems surrounding mine wastes at the regulatory body. But since this is not always the case and even the GARD guide can be difficult to comprehend for a person without mining back ground. It would be nice to have a sorter authoritative “list” to go to about what should be done.

But then again every mine is more or less unique and it is hard to get away with anything less than well-educated persons working with the specific project.

One question that might be interesting to discuss further though is, leaching of harmful elements into the environment. In the cases where you have been involved and potential AMD has been concluded have you always continued with e.g. humidity cell test to see what elements that could be leached that way or has it happened that you just stop at knowing AMD is probable and then recommended treatment of the waste based on that (knowing it is likely to leach harmful elements.)?

(unknown)
8 years ago
(unknown) 8 years ago

For information pertaining to the required test work, permitting, financial security, etc., section 11 of the "Guidelines for Metal Leaching and Acid Rock Drainage at Mine sites in British Columbia" is an excellent resource.

http://www.empr.gov.bc.ca/Mining/Permitting-Reclamation/ML-ARD/Pages/Guidelines.aspx#british%20columbia%20mine%20regulation

Oberfuhrer
8 years ago
Oberfuhrer 8 years ago

Had a deeper look at the MEND site and there are some nice example of projects. What would be really helpful though is a collection of failures due to bad analyzes or too few analyze leading to treatment/remediation that not was enough. Any one knows if this exists?

(unknown)
8 years ago
(unknown) 8 years ago

The classic work on failures in predicted water quality is "Comparison of Predicted and Actual Water Quality at Hardrock Mines": the reliability of Environmental Impact Statements (US)

Jean Rasczak
8 years ago
Jean Rasczak 8 years ago

It is not actually true that there is no regulation applicable to Sweden. First, acid drainage issues have direct connections with the European Union water policy (WFD, EC 2000/60 and its daughters). Second, there was a lot of normative work done by CEN on mining waste. You will find a comprehensive list of relevant standards athttp://www.cen.eu/CEN/Sectors/TechnicalCommitteesWorkshops/CENTechnicalCommittees/Pages/Standards.aspx?param=6273&title=CEN/TC+292. They include guidance. National regulatory authorities in the EU can use them for compliance evaluation.

They are less well known than MEND or GARDGUIDE guidance, because they were issued much later. But there are no big discrepancies.

This is still at the national level:

•The contaminated site policy (and risk assessment issues)

•How local authorities will address the naturally "anomalous" character of a mine site.

For instance, trying to neutralise AMD runoff to the pH6 minimum of the WFD is disputable if the regional water courses show naturally pH5, due to natural ARD and widespread dissemination of sulphide in rocks.

Hope this may help.

Oberfuhrer
8 years ago
Oberfuhrer 8 years ago

I fail to see how the water policy or CEN can regulate how far the analyzes should go. But the links are very nice so thank you. As I said before I agree that what type of analyzes that should be done depends on mine waste and things like how highly valued effected waters are. It is hard to replace well educated ppl with lists, but what I am trying to do at least partly is to gather some easy steps that at least should be used when examining mine waste... that are easy enough to follow for someone not that familiar with mine waste. And to back it up with some authority.

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