Chalice Mining Ltd (ASX: CHN) shares caught the eye on Monday with a stunning gain.

The ASX mining share ended the session 23% higher at $1.48 thanks to some very big news.

But if you think the gains are over, think again.

That's because the team at Bell Potter believes that this speculative stock could more than double in value from current levels.

What is the broker saying about this ASX mining share?

Bell Potter summarises the news that got investors so excited on Monday, it said:

CHN has announced that a major breakthrough has been achieved in respect of metallurgical testwork and process route design for its 100%-owned Gonneville PGE-Ni-Cu-Co Project located ~70km north-east of Perth, Western Australia.

The latest testwork results demonstrate that two saleable, smelter-grade flotation concentrates can be produced across the entire (high-grade and low-grade components) Gonneville sulphide Resource. The process flowsheet now contemplates an industry-standard concentrator-leach-magnetic separation process to produce saleable Cu-PGE-Au and Ni-Co-PGE concentrates plus metal doré, with no need for a hydrometallurgical circuit.

'A gamechanger'

This is big news according to the broker, which has referred to the development as a "gamechanger." It said:

One of the major challenges of the Gonneville Project has been the production of saleable concentrates from the low-grade bulk Resource. The sheer scale of this Resource was strong justification for its recovery. Technical design work had shown an economic route was achievable using (expensive and technically complex) hydrometallurgical processes. However, this latest update shows that the hydrometallurgical process route is no longer necessary and that a conventional flotation circuit can meet the required recoveries and concentrate product quality.

Bell Potter believes that the removal of the hydrometallurgical circuit from the project is material and could reduce costs significantly. The broker adds:

The positive implications of the removal of the hydrometallurgical circuit are multiple and material, including: a significant reduction in capital costs; a significant reduction in operating costs; a lower cut-off grade for a reduced strip ratio; a significant reduction in technical and execution risk; a significant reduction in construction scale and timeframe; and a simplified permitting pathway. The exact quantum of these changes remain to be confirmed with the completion of the Pre-Feasibility Study (PFS), targeted for release in mid-CY25, but this update is emerging as a gamechanger for the Gonneville Project.

Big return potential

In light of the above, the broker has reaffirmed its speculative buy rating and lofty $5.75 price target on this ASX mining share.

Based on its current share price of $1.48, this implies potential upside of approximately 290% for investors over the next 12 months.

Bell Potter concludes:

In our view, the confirmation of a simplified process route will also benefit the financing outlook. The reduced capital requirement makes the project funding less of a hurdle for a company of CHN's size. It also greatly broadens the available pool of capital and potential development partners. Combined with its endorsement at both State and Federal levels as a Major Project, conferring additional support and co-ordination through statutory approvals processes these factors speak to an overall de-risking of Gonneville's development.