Sirius Minerals has entered into a memorandum of understanding for the sale of 500,000 tonnes per annum of polyhalite for 10 years with Sichuan Agricultural Means Group in regards to the York Potash Project.It brings the total committed tonnes to 4.28m per annum.The terms will be at a market price to be agreed at the final contract stage. Sichuan is a major agricultural production company with interests in fertiliser manufacture and distribution in Sichuan and surrounding provinces. It has an annual turnover of 13bn China Yuan Renminbi.Chris Fraser, Managing Director and Chief Executive Officer of Sirius, said: "This is yet another demonstration of the global demand for polyhalite, the importance of the York Potash Project to the UK economy and the strong ties we are developing with China."Shares rose 12.50% to 11.25p at 10:22 on Monday.RD