CONVEYORS
- mile route . We are out in the middle of one of the biggest oilfields in the world with all the associated infrastructure . Then the various private landowners we had to negotiate with and moving into New Mexico a lot of the land is federal BLM owned – we weren ’ t sure initially how that process would play out but it turned out they were very amenable to it and that part moved much faster than we expected . The environmental upside of taking so many trucks off the road was certainly a factor in that . Plus the safety aspect – there is already too much heavy traffic on relatively small roads in that part of the world .”
Atlas also had to be sure that the Dune Express could cross the various roads along the route and that all the relevant county and state level regulatory bodies would give their permission for the crossing structures .
Warner gave some more detail on the crossings themselves : “ We have to cross five public roads with the project along with two others that belong to us , so seven in total . Texas has a road bridge minimum height requirement of 18.5 ft but we were not satisfied with that number because out here there are a lot of oversize loads and quite a lot of bridge strikes . So to make sure we were out of the danger zone we looked at the high voltage lines that never get hit – so we based our heights on the minimum high voltage line heights which means we settled on a 25 ft highway clearance .”
Moving on to the actual design were there any special customised requirements given the climate and the length ? On a high level it is still a basic conveyor structure – Atlas has done some things , however , which are not standard in the industry such as with the idler spacing . The climate is not a worry in terms of the structure as expansion joints have been used throughout every 32 ft which can handle any thermal effects . The conveyor is also covered – this protects against wind losses as it is a 100 mesh ultrafine sand ; and to stop any rain or snow getting to the sand – as it has to be supplied as a fully dry product .
In terms of the process , the sand is actually being mined using a wet mining and processing method utilising an electric dredge , similar to that used in titanium mineral sands mining in Florida and Georgia . Processing is mainly just washing out clays and vegetation and then sizing to a 100 or 40 / 70 mesh . Kermit already has 10 large 5,000 ton silos for sand storage from which trucks were previously loaded – these will now load the conveyor ( or trucks if needed ) via pant leg hoppers . At the other end of the conveyor is another set of similar silos to load trucks for delivery to customers . There are also silos at Atlas ’ s state line facility 16 miles back from the end where loadout to customers from sand diverted from the conveyor can also take place . The Dune Express also has a unique mobile offload facility meaning it has the ability to take sand off the conveyor at any point wherever it makes sense on the ground . Once complete , the Dune Express will have more than 75,000 t of storage capability for sand .
Lastly on to the key components – rollers / idlers , belt etc – what was chosen for this unique project and why ? Warner said full procurement processes were used at all times . On the belting he stated : “ There were four major suppliers in the bidding that were all able to meet our rubber compound requirements . Firstly we needed low rolling resistance rubber , on the non-carry side ie the belt side that is in contact with the rollers , as this brings more efficiency and ultimately lower power cost . On the top we needed to address heat as the sand is capable to being at over 150
M3 ’ s engineering design services
M3 Engineering & Technology ( M3 ) is a company with offices throughout the Americas , and headquartered in Tucson , Arizona . For the Dune Express project , M3 utilised resources from multiple offices to provide structural , civil , electrical and instrumentation engineering design services , which included six seven major overhead road crossings ( five public roads and two that Atlas owns ) using structural steel truss bridges , multiple minor lease road crossings using concrete bridges , and five transfer / conveyor drive stations . While the 42-mile conveyor itself brought its own challenges from a scale perspective , some of the other unique challenges for the project included designing multiple elevated conveyor structures that included both horizontal and vertical curves , numerous design revisions that came about due to interfacing with multiple stakeholders along the conveyor route ( Texas and New Mexico DOT , land owners , existing utility operators etc ), and designing a reliable and robust electrical system to power the conveyor .
The Dune Express will make extensive use of ContiTech ' s CONTI MultiProtect system for belt monitoring
degrees when it hits the belt – while it cools down the line we needed to make sure we could still accommodate that . With a standard compound the heat would pull the plasticisers and oil out of the rubber and quickly destroy it . So we went with a high heat compound that can handle the hot dry sand . And in the end we went with ContiTech . Obviously the best is also a steel cord belt for strength . The belts – some 84 miles of it - were all manufactured at their factory in China and shipped to the US .”
“ We ’ re very grateful to our partners at Atlas Energy Solutions for their trust in our expertise and for the great collaboration on this challenging project . We ’ re confident our belts will make an incredible impact on their operations ," said Andreas Gerstenberger , ContiTech ’ s Head of Industrial Solutions Americas . " From our sales team to our engineers , and everyone in between , the teamwork and collaboration that led to producing premium , incredibly durable belts and fulfilling such a massive order shows we were the right supplier for the job ."
What about the installation such as the winding and splicing of the belt ? Warner states : “ The installation process with conveyors is pretty standard in that they are laying it out and presplicing then pulling it on in long sections . But the lengths they are pulling are not standard – some of these pulls involve almost 10 miles of belt at a time and typically you just don ’ t have that long of a system to pull .”
Warner said that RAM Enterprise is carrying out all the physical installation of the belt including the splicing . Shaw Almex is providing the vulcanising machines and the winders . RAM has stated that it is using six different splicing and flaking yards to splice the ContiTech belt into continuous lengths of up to 52,000 ft , almost 10 miles . Once the structural installation is completed , RAM will string the continuous belt lengths onto the system with the use of highpowered winders from Shaw Almex . RAM has almost 30 employees on site as of February 2024 to carry out this initial splice work , and return within the next few months to complete the vulcanisation and installation of the belting .
All the pre-form splicing kits and belt rubber compounds are from ContiTech , some of which
48 International Mining | FEBRUARY 2024