And topping the rich list has made her even richer. The share price of her company jumped 2.77 percent on the good news, adding another 1.1 billion yuan to her assets.
Wealthier than US television host Oprah Winfrey and author of the Harry Potter series J.K. Rowling, Zhang is described by acquaintances as a "round-faced, not very tall" woman who "doesn't like dressing up and looks like a person of action".
Over the years, Zhang's low profile has helped her remain largely unknown.
"I'm an entrepreneur. A high profile is unnecessary," Zhang was quoted as saying by the Shanghai-based China Business News, whose reporter described her speaking as "extremely fast".
"This title is just a calculation, not a big thing for me," Zhang Yin told a Xinhua reporter last week. "But it's very important for my group. We have worked for 20 years to make the fortune."
The eldest of eight children in a poor soldier's family in northeast China's Heilongjiang Province, Zhang learnt independence at an early age by looking after her brothers and sisters.
She started her career in waste paper trading in Hong Kong with30,000 yuan in 1985 and has stuck with the paper industry since then.
Aspiring to be the "queen of waste paper", Zhang continued to build her realm in the United States by setting up the America Chung Namp, Inc. (ACN) in 1990.
The ACN, whose asset value was not calculated in the rich list, is reported to provides nearly 80 percent of the raw materials for the Nine Dragons Paper.
"The key to the success of Nine Dragons Paper is ensuring the long-term and steady purchase of high-quality waste paper in large quantities," said Zhang.
ACN took good care of that, ranking the largest U.S. exporter of raw materials for paper-making and the biggest container exporter among all US industries for the past five years in a row.liuxuepaper.com