March 7, 2017
Volume 7 Issue 4
Indian Grease Makers Seek Lithium Alternatives
VARANASI, India — For upwards of a year, India’s grease manufactures have had difficulty sourcing lithium hydroxide, a key raw material for making greases thickened with lithium-based soaps. Their woes are unlikely to end soon unless they find alternatives to lithium and lithium complex greases, industry officials said.
Over the past four decades, lithium and lithium complex greases have become the main multipurpose greases for various automotive and industrial applications, according to Vijay Deshmukh, general manager of research and development at Standard Greases & Specialities Pvt.
“The major reasons for the popularity of lithium-based greases are that they have good shear stability, excellent water resistance, high-temperature capability and good response to various additives,” Deshmukh said at the annual meeting of the India Chapter of the United States-based National Lubricating Grease Institute on Feb. 3.
Approximately three quarters of the world’s grease supply is based on lithium, which is also used in lithium-ion batteries that power electric cars, smartphones and laptops. Over 90 percent of India’s grease output is thickened with lithium hydroxide and lithium complex soaps, according to a recent NLGI Grease Production Survey Report. India and the Indian subcontinent produced a total of 76,000 metric tons of grease in 2015.
Lithium, the most popular thickener, is available in abundance in the earth’s crust, but mining the metal at a competitive price and in a useful form is a challenge. Lithium only becomes useful after it has been extensively refined into either lithium carbonate or lithium hydroxide, two of the forms in which the metal is traded.
Lithium, dubbed “white petroleum” for its silver/white color, has witnessed a buying frenzy since mid-2016 as automakers in the United States, Europe and China vie to secure supplies for their electric vehicles. As a result, prices have skyrocketed, and grease manufacturers have been hit hard, especially in India, which is totally dependent on imports of lithium hydroxide as the country doesn’t have native sources to draw upon.
The BMI Lithium Price Index surged 66 percent in 2016, according to London-based battery minerals data provider Benchmark Mineral Intelligence, which produces the index.
“We are most affected by the price increase in lithium hydroxide. So the problem of finding alternatives assumes extra importance for us,” Deshmukh said. Several attendees at the conference agreed.
Eltipu Sayanna, president of NLGI’s India Chapter, said the grease industry in India has been under turmoil lately over the supply and pricing of lithium hydroxide. “It has compelled grease manufacturers to look beyond the obvious and search for suitable alternatives for the same,” he noted.
So what are the alternatives for lithium and lithium complex greases? There are a variety of options, though the best choice depends on the grease application, operating conditions and cost economics, Deshmukh stated. Alternatives include anhydrous calcium grease, aluminum complex grease, calcium complex grease, calcium sulfonate complex grease, mixed base greases and polyurea greases, he added.
“But the most important thing is that these alternatives must be tried and established over a long period of time,” Deshmukh emphasized.
He cited an experiment by Standard, which produced these alternatives in the laboratory and then compared physical and performance characteristics. The grease samples were tested by ASTM/IP test methods, and the data was compared with the BIS IS specifications of lithium base grease and lithium complex grease. The Bureau of Indian Standards (BIS) is an autonomous national standard body in India.
Tests showed that anhydrous calcium grease has properties similar to lithium, except for dropping point, and it can replace lithium base grease in applications in which the maximum operating temperature is around 90° to 100°C.
Aluminium complex grease, polyurea grease and calcium sulfonate grease were compared with IS 14847 specification lithium complex grease. Deshmukh said the data showed that all three alternatives can be formulated to meet the requirements of lithium complex grease for industrial applications.
Deshmukh stated these greases have good dropping points and stability, good water and corrosion resistance, and better load-carrying ability than lithium-based products. He noted that aluminium complex grease and polyurea grease have added advantage of better pumpability.
“Polyurea grease appears to be most promising alternative to lithium complex grease in terms of its properties and cost,” Deshmukh said. However, the handling of toxic raw materials is a major concern in manufacturing of polyurea greases, he added.
In general, the cost of producing aluminium complex grease, polyurea grease and sulfonate complex grease would be on par or 10 percent higher than the lithium complex grease based on the current cost of lithium hydroxide, he added.
However, there’s high probability that costs will continue increasing, and the ready availability of these alternatives would help mitigate the impact, Deshmukh concluded.