Story audio is generated using AIGold Fields expects first-half earnings to rise as much as 90% as higher gold production and a stronger gold price boosted its performance.It is maintaining its production guidance for 2026 despite operational challenges at two of its mines.HEPS for the six months to end-June is expected to be between $1.98 and $2.18, up 72% to 90% from a year earlier, the gold miner said on Tuesday.Adjusted free cash flow before discretionary investments is expected to rise by 91% to 111% to between $2.39bn and $2.64bn.Gold Fields attributed the increased earnings to higher sales volumes and a stronger realised gold price, partly offset by a higher cost of sales. First-half attributable production is expected to increase 12% to 1.26-million ounces, while costs to sustain production are expected to rise 13% to $1,900/oz. The company said it remained on track to meet its full-year production and cost targets, with output expected to be at the upper end of its 2.4-million ounce to 2.6-million ounce range.The gold miner said lower expected production at the Gruyere mine in Australia and Tarkwa in Ghana would be offset by stronger output from Salares Norte in Chile, which is expected to exceed its full-year production guidance.Gruyere increased production by 25% in the second quarter from the previous three months as mining operations improved. However, Gold Fields said the mine remains at risk of missing its annual production target because of high contractor labour turnover and lower equipment utilisation.Production at Tarkwa also improved in the second quarter but the mine is also at risk of falling short of full-year guidance after a weaker first half.Capital expenditure guidance has been reduced to between $1.6bn and $1.8bn, from $1.9bn-$2.1bn previously, mainly because some expenditure at the Windfall project in Quebec, Canada, has been reclassified from capital expenditure to exploration expenses. Gold Fields said it now expects environmental approval for the Windfall project in the second half of the year, after which it plans to proceed to a final investment decision. It expects project capital to be at the upper end of its previously guided $1.7bn-$1.9bn range.Business Day reported in November that Gold Fields is doubling down on investing in the Windfall project with conservative assumptions for first gold in 2029, with upside for 2028 dependent on approvals.In October 2024, Gold Fields acquired Osisko Mining, with 100% ownership of the Windfall project and the extensive surrounding exploration camps.Windfall was previously jointly and equally owned by Gold Fields and Osisko. It consists of three key properties: the Windfall project and the Urban-Barry and Quévillon exploration properties.Windfall is among the largest gold deposits in Canada and a top 10 gold deposit globally by head grade. It is said to be Canada’s second-largest undeveloped gold mine by value, according to a 2022 feasibility study. Gold Fields plans to spend at least $1.7bn on the mine in the five-year planning period.Gold Fields is due to publish its interim financial and operational results on August 25.Business Day