Net Sales

9 Months Ended

Sep. 30, 2021

Revenue From Contract With Customer [Abstract]

Net Sales

10.  Net Sales

Disaggregated Net Sales

As discussed in Note 1, we primarily derive our revenues from the sales of various chemical products.  The following table presents our net sales disaggregated by our principal markets, which disaggregation is consistent with other financial information utilized or provided outside of our condensed consolidated financial statements:

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2021		2020		2021		2020
	(In Thousands)
Net sales:
Agricultural products	$	51,102	$	31,986	$	162,523	$	138,441
Industrial acids and other chemical products		63,920		32,372		164,803		97,137
Mining products		12,177		9,611		38,685		26,835
Total net sales	$	127,199	$	73,969	$	366,011	$	262,413

Other Information

Although most of our contracts have an original expected duration of one year or less, for our contracts with a duration greater than one year at contract inception, the average remaining expected duration was approximately 12 months at September 30, 2021.

Liabilities associated with contracts with customers (contract liabilities) primarily relate to deferred revenue and customer deposits associated with cash payments received in advance from customers for volume shortfall charges and product shipments.  We had approximately $1.7 million and $2.5 million of contract liabilities as of September 30, 2021 and December 31, 2020, respectively.  For the three and nine months ended September 30, 2021, revenues of $0.6 million and $2.2 million, respectively, were recognized and included in the balance at the beginning of the respective period. For the three and nine months ended September 30, 2020, revenues of $0.6 million and $1.5 million, respectively, were recognized and included in the balance at the beginning of the respective period.