Developed after high quality limestone deposits were uncovered in an existing quarry, today Linwood ranks as one of the largest underground limestone mines in the country.
Two distinct ledges of operation yield high-calcium limestone and dolomitic lime. Both ledges meet Iowa’s highest level of classification for concrete aggregates. In addition, the high purity of Linwood limestone makes it ideal for chemical production.
The Linwood mine operates twelve months a year and mines roughly 32 acres annually. In addition to limestone production, the mine also serves as a site for additional activities. A subterranean shop and office area allow for onsite equipment upkeep and careful monitoring of mining operations. Safety and corporate training also take place below, as well as fabrication and water storage.
After stone is extracted from the mine, it is transported to a primary crusher. Following the initial crushing process, the material is then sized and screened in accordance with customer specifications. Finally, Linwood products are either stockpiled or transported to the chemical plants for further processing.
Linwood’s Lime Plant is a full time operation, operating 24 hours a day for 365 days a year. The Plant features four kilns, two of which are fully automated. All processing is carefully monitored in computerized control rooms.
The Lime Plant uses limestone from Linwood’s underground mine to ensure that production begins with high quality materials. In addition, the lime plant produces both high calcium and dolomitic lime and provides both varieties in pebble and granular form.
Once limestone has been calcinated in the kilns it is sent to our screening tower where it is sized to specification. The lime is then placed in storage bins where it awaits transportation or bagging.
New technology also exists in the Linwood bagging facility. Lime products are carefully measured via a computerized system of weigh belts and volumetric meters that provides both accuracy and uniformity in the bagging process. This system also makes product blending and custom bag sizing significantly easier and more efficient.
Linwood’s ideal location makes several methods of product transportation feasible. The plant’s close proximity to Interstate 80 makes shipping via truck convenient. In addition, many of our products are available in both bags and bulk, so both pneumatic tankers and grain hauler trucks are appropriate for transport.
Linwood also boasts an onsite ICE/DME railroad line with daily service. This connection makes efficient rail hauling possible, as most major railroads connect with this line.
Linwood is also able to offer barge shipping to its customers. The company’s setting on the Mississippi river makes both local and long distance shipping possible. Linwood is located at mile marker 475.3.
The processing plants in the quarry operate two shifts 5 days a week nearly 24 hours a day. The processing plants include a primary impact crusher, and three gyratory crushing, screening, & wash plants. From the quarry, 55% of the product is shipped by truck, 35% by barge, and 10% by rail.