The paper discusses the architecture and development of an Argument Workbench, which is a interactive, integrated, modular tool set to extract, reconstruct, and visualise arguments. We consider a corpora with dispersed information across texts, making it essential to conceptually search for argument elements, topics, and terminology. The Argument Workbench is a processing cascade, developed in collaboration with DebateGraph. The tool supports an argument engineer to reconstruct arguments from textual sources, using information processed at one stage as input to a subsequent stage of analysis, and then building an argument graph. We harvest and preprocess comments; highlight argument indicators, speech act and epistemic terminology; model topics; and identify domain terminology. We use conceptual semantic search over the corpus to extract sentences relative to argument and domain terminology. The argument engineer uses the extracts for the construction of arguments in DebateGraph.