Mining companies use a new technique to present future mining plans
Powder bed and inkjet head printing is more costly than plastic extrusion deposition printing. To create the print, powder plaster or resin is deposited with a binder by an inkjet-like apparatus that builds the model layer by layer. (Photos: Cypress 3D Printing)

Recent advances make 3-D printing an economical means of creating multipurpose models that effectively present technical information to laypersons, such as those found in public consultation meetings, according to a consulting company that specializes in the technology.

Compared to previous generations, current 3-D printing technology, sometimes referred to as additive manufacturing, is now less expensive, more user-friendly and faster, said Matt Blattman, owner of Cypress 3D Printing (www.cypress3dprinting.com). In mining, it is an emerging technology enabling the creation of models specialized for cost, audience and purpose. Cypress 3D Printing recommends its use when creating visual representations of information, such as mine plans and geologic interpretations, to be delivered to external (non-technical) customers. With 3-D printing, what was traditionally expressed by maps or posters, which can be challenging for laypersons to interpret, can instead be expressed by models. There are a number of printer types, but the company summarized the three most common types in a recent presentation.

The least expensive 3-D printer type is commonly carried by various retailers, such as Sam’s Club and others. Extrusion-based 3-D printing (fused deposition modeling) takes raw plastic material, runs it through a hot end, similar to a hot glue gun, and lays it down in beads to build up a 3-D model. If the model is of a building structure or a pit design, the print will emerge layer by layer, building upward.

Extrusion deposition 3-D printing is low-cost but also comparatively less precise. To generate prints, plastic beads are deposited by a nozzle head in layers.

Low cost makes this print process attractive, said Blattman, a mining engineer. The capital cost in purchasing an “extrusion-based machine is in the range of hundreds to a few thousand dollars,” he said. Further, the materials, usually low end plastics, are cheap. A 2-pound (lb) roll of material currently costs roughly $50.

“The sacrifice is you get a much less precise 3-D printer,” Blattman said. It provides a more abstract model because product shape, texture, definition and color will be limited, he said. “You are going to get models that are a single color and you’ve got to take that into consideration.”

More expensive and dynamic, powder bed and inkjet head 3-D printing creates models from digital and orthophotographic data, Blattman said. To portray a plant or mining sites, inkjet head printing uses high-resolution raster images, line data or text data, which is conveyed by the print. Further, it incorporates full color into the design.

“The printer repeatedly puts down thin layers (0.1 mm) of fine-grained powder of some form, usually gypsum powder or plastic powder. It infuses the powder with colored binder to build the model,” he said. The model will be more precise and complex than it would be had it been generated by an extrusion-based printer.

Inkjet head printing, however, can be costly. “You have jumped up from hundreds of dollars to thousands of dollars for both the material cost and the machinery,” Blattman said. Also, the resulting print can be fragile. “Just because you can print a part doesn’t mean that it will be able to be transported to any locations. It is very much like a ceramic and can be less durable in that regard.”

At the high end of the 3-D printing spectrum, Continuous Liquid Interface Production (CLIP) applies a laser or ultraviolet light to a liquid or resin to shape and bind printing materials and build up models. It generates more exact models made from finer materials, Blattman said. “What’s great about this is you are going to get a much better print. You can get high precision,” he said. “You can even add an element of transparency to the model and put multiple materials together.” The drawback is CLIP is “by far” one of the most expensive methods of 3-D printing. Further, “if your intent is presenting information to a stakeholder that needs photographic information or textual information, you are not going to be able to put that in as easily, as the range of colors are more limited than inkjet-based printers,” Blattman said.

Three-dimensional prints vary in cost, color, technical accuracy, durability and component materials. This stereolithographic print conveys geological strata, orebody seams and an open-pit mine plan.
Case Studies: Modeling Mining Operations

A crushed stone company headquartered in Virginia approached Cypress 3D Printing, seeking a way to present information to regulatory agencies. They also sought a medium with community education capabilities, Blattman said. “The company plans to fill these quarries with lakes when they are done,” he said.

Powder bed printing can incorporate orthophotographic data and full color. A model with breakouts can convey phases of an operation or alternative plans, which can then be presented to a non-technical audience such as a regulatory committee.

“They needed a removable piece. One model shows the before information of the pit design,” he added. “The second is the same model with the lake pieces.”

The resulting model exceeded their requirements. It conveyed the needed information to a non-technical audience. The stakeholders were a regulatory committee that may not have been experienced interpreting maps. The drawback was expense. 3-D prints pertaining to short-term planning may be cost prohibitive, Blattman said. “If you use it for short-term planning, and you have to reprint and reprint every year, it can be costly,” he said. “If you are doing a life-of-mine or long-term mine plan, it makes a lot more sense.”

Stereolithography or resin printing creates encapsulated models via photopolymerization, the process of light fusing molecules, creating polymers, layers of which comprise a 3-D solid.

Similarly, a mining company headquartered in Chicago sought a model to present to investors. They needed something to show the impact of the expansion of their mine, and to “give some context,” Blattman said. “They wanted a 3-D mine plan with removable pieces. In this case, we got a little more involved in the presentation, actually going into their digital data and doing some preparation for print. This one was a little more involved where you have different stages and you have alternatives to the pits they are trying to portray to their investors, showing that the sequence of events over time. It’s a bit bigger of a model as well.”

The model enabled expression of technical information to a non-technical audience; however, the company used it internally as well. “What they found, though, is it also worked well for operations,” Blattman said. “They would bring the model into the meetings for operators and use it as a point of reference. They could then bypass maps.”

A third client, an earthmoving operation with substantial amounts of cut and fill, sought a model that would convey volume changes, where they were going to be cutting next, and the sequencing for each new operation location, Blattman said. “Alternatively to the other ones, there was no photographic information,” he said. “It was all textual information that they could take into their day-to-day operations and explain what their long-term plan is and what their short-term plan is to operators, and show what kind of information they can get across.” Notably, they found that they used the model daily, which is not uncommon. A model planned for one purpose often is discovered to be useful for other ends.

There are a number of 3-D printing technologies beyond those described here, to include hybrids. Determining which is most suitable for your needs depends on your budget and your purpose, Blattman said. “That is usually the decision matrix for most things in this industry,” he said.

The presentation “Emerging Technologies in 3-D Printing” was delivered by Blattman Brothers Consulting, forerunner to Cypress 3D Printing, at the 2016 Society of Mining Engineers meeting, held in Phoenix in February. Blattman can be reached at contact_us@blattbros.com.