The modified/immobilized/stabilized tailings were cured saturated in mine water for two years prior to leachate testing. As I have alluded to before, the heavy metals, chlorides and sulphates have been locked up unable to leach.
Hydraulic backfill in this mine is problematic with constant...
Absolutely no offence taken SlideRuleEra. I welcome all criticism. I'm glad you agree that it's difficult to convince the naysayers.
If you always do what you always did, you'll always get what you always got!
I have been working on this for about 10 years on and off. I have recently revisited the process as the mine company is running out of space at the tailings dam. I've had the tailings briquetted with a low cement content (with additive) and at low moisture content. The pellets pass the drop...
All toxins have been successfully bound and immobilized sufficiently. So much so that the formed product has been assessed under the Dutch Soil Quality Decree. It is suitable to be used beside water courses. This material if blended into a concrete would also be deemed inert for landfill...
I have a lightweight mortar from Lead/Zinc tailings. The tailings had a high sulphate content that has been reduced to 0.28% water soluble sulphate and 1600ppm sulphate. If crushed, could this be used as a lightweight aggregate in concrete?
Thanks miningman, but the rock mechanics don't seem to be annoying this material even with 50 tonne axles. It's not the compressive strength of this material that matters but the fact that it can withstand repeated stresses with limited micro strains therein. The RCC seems to be behaving like...
The additive I have used is ConcreCem, produced by PowerCem BV in Holland. I have also had concrete tested beyond the hydrocarbon fire curve(1250C) for 50 minutes. This concrete had no fibres and did not spall explosively nor melt! I have also produced a self levelling cementitious floor...
Thanks for the replies.
My situation is a mine haul road 1000m underground. I've already laid a modified RCC almost 2 years ago with an additive which prevents thermal expansion and renders the concrete 'flexible'. This material had 8% OPC and achieved 32MPa compressive and 10.2 MPa flexural...
I am about to oversee a project involving the placement of RCC in an environment where the temperature remains at a constant 70 degrees fahrenheit. My question is do I need to saw cut expansion joints?
Thanyou geomtl,
I see where the problem of cracking and rising of floor slabs has occurred here in Ireland. Automatically pyritic oxidation has been blamed. The fill material below the slab was a limestone. Is it fair to automatically place the blame on the aggregate, or can other forces be...
Thanks Stego1,
Are you aware of any European legislation or directives relating to maximum permitted levels of pyrite, or does each member country have its own?
Is anyone aware of any specifications, anywhere, for maximum permitted levels of pyrite in building products and in particular fill material for use below concrete slabs in house construction?
I've been asked to confirm a design for a road job in southern India. The design is for 1 million axles for a 15 year period. Specification is for 200mm sub-base, then 250mm hydraulically bound material, topped with 60mm base hma and 40mm wearing course hma. The sub-base cbr is 8. Is this...
BigH,
It's not a British thing! The Brits just request non-plastic GSB.
The reason given for the use of LL as a control of sub-base materials in Ireland as given to me is as follows ;'The simple answer to your question is that when we used other methods of
>controlling fines such as you are...
