(Adds quote from Barrick executive, details of plan)
By Maximilian Heath
BUENOS AIRES, April 21 (Reuters) - Barrick Gold Corp and its new Chinese partner presented a $500 million plan on Friday to make safety and environmental improvements to the Veladero gold mine in Argentina after a third cyanide spill in 18 months, a company executive said.
Argentina told Barrick earlier this month it had to overhaul environmental and operating processes at the mine following the latest spill on March 28.
"We've got a plan over two years to invest half a billion dollars to develop Veladero operations," Barrick Chief Operating Officer Richard Williams told reporters after meeting government officials in Buenos Aires.
Local authorities say the company needs to make improvements in pipelines and in its control and monitoring systems as well as expand its leach processing facility.
Barrick will submit the technical plan next week, Williams said. "The leach pad is going to be extended and developed and improved. So it's going to be re-engineered."
Argentina's Energy and Mining Minister Juan Jose Aranguren said that analyzing the plan would take about two weeks and approval would depend on guarantees of investment by Barrick aimed at improving safety at the mine.
Barrick, the world's largest gold miner, has been temporarily restricted from adding cyanide to the mine's gold processing facility in Veladero, although other operations continue.
Alberto Hensel, mining minister of San Juan province where the facility is located, told local radio he hoped the sale of 50 percent of the mine to China's Shandong Gold Mining Co announced this month would improve its operations.
"What we know about Shandong is that it is a company that has extensive experience meeting the highest environmental standards, which we believe will contribute to the improvement of the Veladero mine," Hensel told radio station Radio Sarmiento in San Juan on Thursday evening.
The Toronto-based company, which counts Veladero as one of its five core mines, says no material impact was expected on the mine's projected 2017 production.
The provincial government, which rejected a first work plan from Barrick on April 5, is still evaluating a potential fine for the company for the March 28 incident.
Hensel said penalties could surpass the $9.8 million the company was fined for a 2015 spill. A fine has not yet been applied for a September 2016 incident in which solution containing cyanide flowed over a berm. (Reporting by Maximiliano Rizzi and Maximilian Heath; Writing by Hugh Bronstein and Caroline Stauffer; Editing by Chizu Nomiyama and Bill Trott)