Shaft Design Specialists

22 November 2011

Sirius Minerals Plc

("Sirius" or the "Company")

Shaft Design Specialists

The Directors of Sirius Minerals Plc (AIM: SXX, OTCQX: SRUXY), the globally diversified potash development group, wish to announce the appointment of mine shaft design specialists Alan Auld Engineering Ltd of Doncaster, England to develop lining design and sinking concepts for the York Potash Project in North Yorkshire, England.

This world-class potash project will involve sinking new shafts to well over 1,000 metres through highly varied strata and will require a shaft lining which can withstand high hydrostatic loadings, as well as being able to accommodate strata subject to deformations and time dependant creep.

Alan Auld Engineering is a world class engineering and mine support company specialising in the design of deep shafts and tunnels for mine access. The company is well known for its shaft design work for salt and potash mines around the world and is very active in a number of current sinking and relining projects. Alan Auld Engineering is probably one of the most experienced deep shaft designers in the world and brings state of the art knowledge to this exciting project, including experience in the fields of ground freezing and recent developments in shaft sinking technology, having worked with German machine supplier Herrenknecht AG in the development of a mechanised shaft sinking system.

In addition, Alan Auld Engineering are developing innovative concepts for low-profile, low visual impact mineheads and shaft headframe sub-structures. As Sirius looks to reduce the environmental impact of the York Potash Project, Alan Auld Engineering will provide vital input into those designs and planning concepts.

Sirius is still collecting the necessary data upon which to base its decision on the exact location of the minehead for the York Potash Project, but in the meantime is keen to advance all design and other matters that would be common to any shaft whatever its location.

Chris Fraser, Managing Director and CEO of Sirius said:

"The design and construction of the shafts for the York Potash Project are of critical importance to the successful rapid development of the project. Alan Auld Engineering is a world leader in this field and is currently developing new lining concepts to enable the implementation of the innovative and potentially transformational Herrenknecht shaft sinking systems.

"Given the location of the York Potash Project, we recognise that minimising the visual impact of the ultimate minehead location will help maximise our chances of continued community support. Alan Auld Engineering is one of the firms leading the world in these designs and will be an important partner for Sirius going forward."

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About Sirius Minerals Plc

Sirius Minerals is a globally diversified potash development company. Its primary focus is to bring on stream major potash mining facilities through the acquisition and development of projects overlying recognised potash deposits. Today it holds properties in the United Kingdom (North Yorkshire), the United States (North Dakota), and Australia (Queensland and Western Australia).

The Company is additionally progressing ongoing innovation initiatives into the secondary uses of salt and potash beds for energy storage and carbon dioxide sequestration.

Incorporated in 2003, Sirius Minerals' shares are traded on the London Stock Exchange's AIM market. Its shares are also traded in the United States on the OTCQX through the use of a sponsored ADR facility. Further information on the Company can be found at www.siriusminerals.com.